The 5 Best Deals From Costco's September 2023 Coupon Book

What's better for your personal finances than Costco prices? Costco sale prices, of course. And we're smack in the middle of all the sales from the September 2023 Coupon Book. (Deals extend through Sept. 24, 2023.)

Of course, the best deals are subjective -- the best deal for you is going to be a sale for something that you'd already planned (and budgeted) to buy. But here are a few stand-out deals that offer the best prices we could find on some well-regarded products.

1. Get $300 off: Yardistry Greenhouse

We're coming up on the time of year to consider how you'll over-winter all those lovely garden plants. The greenhouse from Yardistry is well-reviewed and looks like it will hold up for seasons to come.

Regular price: $1,499.99

Sale price: $1,199.99

Discount: 20%

2. Get $150 off: Casper Memory Foam Mattress

Ideally, we spend eight hours a day in our beds, so they should be comfortable. While the Casper Select 12" Memory Foam Medium-Firm Mattress isn't for everyone -- about 5% of reviews are 1-star -- it has a 4.4-star rating on Costco.com, so it must work for more folks than it doesn't. As far as mattress prices go, the sale price is solid for a queen-size memory-foam mattress.

Regular price: $649.99

Sale price: $499.99

Discount: 23%

3. Get $140 off: Samsung 3.1.2 Channel Soundbar

Surround sound has become increasingly less necessary as soundbar technology improves. The Samsung 3.1.2 Channel Soundbar (HW-S80CB/ZA) has decent reviews around the web. If you're looking to upgrade your home audio setup, this could be a great deal for you.

Regular price: $699.99

Sale price: $559.99

Discount: 20%

4. Get $50 back: P&G rebate

Folks who don't mind a couple extra steps in their savings can get a decent return on most P&G items this month. If you spend $100 on eligible items, you can get $25 back (as a Costco Shop Card). Another $100 in spending will get you an extra $25, for a total of $50 max back per membership number. You'll need to scan your receipts online as proof of purchase to get the Costco Shop Cards.

Regular price: $200

Sale price: $150 (after rebate)

Discount: 25%

5. Get $40 off: Keurig K-Supreme Plus bundle

If you're still using an older Keurig model without the water reservoir, then consider an upgrade. (No one enjoys trying to pour water out of a mug into a tiny opening while half asleep.) This Costco bundle also includes 18 K-Cup pods to try, including a few Kirkland Signature blends. It also has a reusable coffee filter so you can use your own beans.

Regular price: $139.99

Sale price: $99.99

Discount: 29%

Picking the right card for high-ticket items

A lot of the deals this month are for fairly substantial purchases, like electronics and furniture. As such, you should give a little consideration to how best to protect your pricey products.

Costco's satisfaction guarantee is pretty awesome; it has a long return window, and most reports are that Costco will take care of complaints quickly and easily. However, it does have its limits. Most electronics and appliances, for instance, are only returnable within 90 days of purchase. And what happens after that?

A lot of rewards credit cards also happen to offer various purchase protections that could come in handy here. Of particular interest may be the extended warranty feature on some cards, which doubles the manufacturer's warranty on all sorts of items.

Check your favorite rewards cards to see if they offer any useful purchase protections. Don't forget that Costco only accepts Visa credit cards.