A pile of pennies

Sometimes worrying about pennies turns into lost dollars. Image source: Pixabay.

Not eating for a month would technically save you a lot of money. So would no longer paying your electric bill, or skipping much-needed medication.

Of course, it's easy to see why those are really bad ideas. You might save money with them for a bit, but there's no way you could fail to recognize that their ultimate cost to you would be high.

However, there are other ideas that seem like they'd be good ways to cut your costs, but in practice, don't actually save you money. The challenge is identifying which ones are good ways to save a few dollars (we examined 20 of them here) and which are fundamentally flawed.

Although the ideas below might seem like good money-savers, for most people, they don't work.

A stethoscope on top of medical papers.

Unexpected health problems can ruin your finances. Image source: Pixabay.

Getting health insurance that only provides catastrophic coverage

It's possible to buy insurance that offers only what's called "catastrophic coverage": It pays your medical bills, but (other than for a few very basic services) only kick in should you have a major, expensive health issue. These plans are generally only offered to people under 30, and they come with low premiums but very high deductibles.

The logic behind this is that younger folks have lower chances of getting sick and needing to use their health benefits. A catastrophic plan is essentially a bet that you won't need much health care, hedged with a bet that will keep you from going bankrupt if something really bad happens to your health.

Consumers insured via the ACA marketplace would have to pay $7,150 in health expenses before the insurance company assumes responsibility for any further bills, according to HealthCare.gov. That's a bet worth taking only if you have $7,150 available in case you actually get sick. If you don't, it makes more sense to pay a higher monthly premium for a plan with a much lower deductible -- especially given that young, healthy folks generally pay lower premiums for regular health insurance anyway.

A pair of sneakers

Buying cheap sneakers could cost you more in the long run. Image source: Pixabay.

Buying low-quality clothing or shoes

If one pair of jeans costs $20 but will wear out after six months of normal use while a second pair costs $50, but will hold up for years, then the cheaper pair is not actually a "deal." This principle is especially true when it comes to shoes and sneakers, where cheaper can not only mean less durable, but also less well-designed. Wearing ill-designed can lead to foot or back problems.

Oil being poured into an engine.

Skipping oil changes can lead to engine damage. Image source: Getty Images.Skipping oil changes/other car maintenance

Skipping oil changes

If someone told you that skipping your annual medical checkup was a clever way to save money, you would probably realize that the risk would not be worth the reward. The same is true when it comes to your car: Skimping on oil changes and other routine maintenance might keep a few bucks in your pocket for a while, but eventually, neglecting those upkeep expenses will almost certainly result in a major, expensive breakdown down the road.

A hammer, screwdriver, and pliers on a workbench.

There are some repairs you can do yourself and some best left for a professional. Image source Pixabay. https://pixabay.com/en/tool-work-bench-hammer-pliers-384740/

Trying to be a do-it-yourselfer on the wrong things

There are lots of little home repairs most people can do themselves, perhaps with a bit of guidance from online videos. For example, it's relatively easy to patch drywall or fill in the nail holes left when you take down a painting that was hung on the wall.

In many other cases, however, unless you have appropriate training, it'll be cheaper in the long run to use a licensed professional. For example, it's never a good idea for an amateur to do electrical work, and in most cases, plumbing should be left to plumbers, lest you turn a small problem into a larger one.

Cars on a car carrier.

Not having car insurance is a bad idea if you have an accident. Image source: Pixabay.

Not having car insurance

Amazingly, in a few states, there is no legal requirement to have car insurance. The problem with that is while it may save you money in the short term, the decision could bankrupt you. If you cause an accident, damage to the cars won't be your only financial concern: You'll also have to worry about injuries to other drivers. Car insurance covers the medical expenses for anyone who gets injured in an accident. If you don't have it, you're liable, and healthcare costs start adding up fast.

In some cases, if your car has little replacement value, it's OK to only have injury and liability coverage -- but it's never a good choice to go entirely without.

A doctor wearing a stethoscope

Not getting an annual physical can lead to financial and health costs. Image source: Pixabay.

Skipping your annual checkup

In many cases, skipping a yearly physical won't even save you money, because your health insurance will pay for it. But even if there are portions of the bill or tests not covered, spending that money gives you a far better chance of discover potential health issues early, when they might be prevented or treated at much lower overall cost. Wait to see a doctor until a medical problem becomes acute, and it might not be treatable at all.

A 40% off sale sign

Saving money does mean you did not spend money. Image source: Pixabay.

Forgetting that it's not what you save, but what you spend

When they buy a $50 sweater at 50% off, most people perceive that situation as one in which they saved $25. In reality, it's not about what you save, but what you spend. Regardless of the discount, you still spent $25, and that's how you have to look at it or else you can bankrupt yourself "saving" money.

A dollar sign with an arrow meant to signify a rebate or money coming back

A rebate only counts if you redeem it. Image source: Getty Images.

Falling for rebates you won't redeem

How often have you made a purchase because the item was being discounted, but in order to receive the rebate, you had to mail something in? In that scenario, most of us have good intentions: We expect to send the rebate in, so we factor that into the mental calculation about how much the item costs. In reality, only around 40% to 60% of rebates actually get redeemed, and the companies that offer them usually don't make redeeming them easy. So you need to be very honest with yourself when making a purchase about your odds of being one of the folks who will go to the trouble of getting that money back.

Toy chattering teeth with googly eyes on top

Going to the dentist twice a year can prevent larger problems. Image source: Pixabay.

Skipping the dentist

If you go to the dentist twice a year, you can prevent bigger, more expensive problems from happening. Skipping a visit may seem like a way to save some money, but that won't be the case if a small issue, left unattended, results in you needing a root canal, a crown, or even both -- which can cost thousands of dollars.

A bowl of cereal with milk being poured into it.

Cereal can be tempting at warehouse clubs, but remember it can go stale. Image source: Pixabay. https://pixabay.com/en/cereal-spoon-milk-cheerios-1444496/

Buying food in bulk only to waste it

Warehouse clubs can save you a ton of money, but only if you buy things you need and will actually use. Buying a palette of croissants and throwing half of them away because they go stale before you can eat them means you actually spent twice as much per pastry as you thought. The same is true with anything else you might buy in bulk. It's only worth it if you will actually use it, and wastage has to be figured into the cost. (Also, recall the previous slide titled "Forgetting that it's not what you save, but what you spend." Buying something you wouldn't otherwise, just because the price is so great, is not "saving.")

Batteries

If batteries are not included, but are needed, you have to figure them into the price. Image source: Pixabay.

Buying something at a bargain price...when that's not the whole price

If someone tries to sell you a car at a certain price, then tells you the steering wheel will cost extra, you'll obviously recognize you have to factor that into your total cost. But there are many less obvious cases where making your purchase actually work requires additional outlays -- which means the price you pay up front is not the real price. For example, if you buy a video game console that does not come with a controller, until you buy one, it's really just a pretty box, so you have to factor in the cost of one.

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