There are many reasons people will give for why they got tattoos. That's fine, but anyone considering one should weigh the pros and cons. And before you move on to another article because you're not in the market for a tattoo, consider sticking around. Many of us are mulling some major discretionary purchase, such as a massive TV, a big vacation, or fancy options on a new car -- and some of the points I'll make apply to any big purchase. Before you spend any major money, ensure that you're making the best investment.

The basics
Let's back up a bit, though, and review some basic things to know about tattoos.

Costs: Tattoo costs vary widely, depending on the size and complexity of the tattoo you want and the skill and prominence of the tattoo artist you hire. Some are priced by the job (via a flat fee), and some by the hour. Designs available and on display at a tattoo shop are likely to have a flat fee associated with them. Custom work tends to be charged by the hour, at the shop's rate, which generally range between $50 and $300 per hour. Thus, a small tattoo might cost as little as $50 or so, while a big "sleeve" tattoo might cost $2,000 or more. (The digging I did online suggests that these might cost $1,200 or less, or more than $10,000. You might need to shop around to find the best tattoo investment.)

Upkeep and fading: Not everyone realizes it, but tattoos can fade over time. To minimize damage, it's best to apply sunscreen before spending much time in the sun -- though not with new tattoos, which need special care. Note that tanning beds are not tattoo-safe, either, and can damage your inky investment.

Risks: As you might suspect, tattoos are not without risks, such as allergic reactions to dyes used, skin infections, keloid scarring, and diseases such as hepatitis, which can be transmitted by contaminated tattooing equipment. Other risks include having a poor tattoo artist botch the job in some way, or you may change your mind later and regret the tattoo.

Removal: It's far from unheard of for a tattoo bearer to want to get rid of a tattoo. One estimate of the tattoo remorse rate is 16%, or about 1 in 6. Removal can be expensive and painful. Effective removal by laser can cost five or six times the original cost of a tattoo to have it removed, and it might take more than a dozen sessions. You may see tattoo-removal creams available, but know that they may not be your best investment, as there's little evidence that they work well. They might, at most, lighten the tattoo -- but it will still be there. And some creams or treatments might hurt or scar. Proceed with caution.

Financial problems
As you mull getting tattooed, give financial issues some considerations, too. For one thing, having one or more tattoos can get in the way of your landing or keeping your job. In some circumstances, employers can require that you not have tattoos visible, such as when you deal with customers. Thus, the location of your tattoo matters, with some much easier to conceal than others. Some of the many employers that have, or have had, no-visible-tattoo policies include Disney, Starbucks, Denny's, and the U.S. Postal Service. According to an annual survey by the Center for Professional Excellence at York College of Pennsylvania, 61% of human-resource managers have said that a tattoo would hurt a job applicant's chances, while a 2011 survey by CareerBuilder found 31% of surveyed employers saying that a visible tattoo would dissuade them from promoting an employee. (Note, though, that since a fifth of Americans now sport tattoos (and 38% of those are aged 30-39), attitudes at workplaces may well change.

Another major financial concern regarding tattoos (or any major purchase) is their actual cost. The price on the bill that you pay is one cost, but there's another -- the opportunity cost. That's what you're giving up by spending the money on the tattoo. The $300 spent on a tattoo (or $5,000 spent on many tattoos) might alternatively have gone into a retirement account, for example. Imagine that you're a 25-year-old who spends $2,000 on one or more tattoos and might alternatively invest that money in an S&P 500 index fund for 40 years, until retirement. Well, if that money grows at the stock market's long-term average rate of roughly 10% annually, it would amount to $90,500. Retire at age 70, as many of us might need to do, and that $2,000 could top $145,000!

So now step back and ask yourself whether that $2,000 tattooing is still the best investment for you. Maybe it is, given all your other considerations. But if you haven't given much thought to your alternatives, do so. Parking that money in the stock market could fund a comfier retirement.

The best investment
The bottom line is that before you plunk down any serious money, ask yourself whether you're making the best investment with it. Instead, your best investment might be opening a tattoo or tattoo-removal business. For most of us, though, big sums of money are best spent keeping ourselves out of debt and plumping up retirement accounts to build a more secure future.

Longtime Fool contributor Selena Maranjianwhom you can follow on Twitter, owns shares of Starbucks. The Motley Fool recommends and owns shares of Starbucks and Walt Disney. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.