I'm a rebel who thinks that rules are meant to be broken. Costco on the other hand can't get enough of rules. You have to spend $55 a year for the privilege of shopping at their store and then you need to carry yet another plastic card around in your wallet in case you ever want to shop there. Want to make an impromptu Costco stop but you left your card at home? Thats a 20 minute wait in the membership line. Have a Visa? Too bad for you - Costco is Mastercard only, and damn do they love their Mastercard. If you've found a way to wait in the giant lineups without getting harassed by someone to sign up for a specialty Costco Mastercard, let me know. For now I'll assume it's impossible.
You need to be open to buying what they have, not what you want. Costco changes all the time. I'm pretty sure a case studies on Costco in one of my university classes taught us that Costco only carries a set number of products regardless of category. This means that river rafting floats might get the boot for watermelons. Think makes it so you can't go here to buy a product you want. You simply need to walk in with your wallet open willing to buy whatever they have... and 300 of them. Or say you waited in a 20 minute membership line so you could have the privilege of shopping at the store that you pay $55/year to shop at so you can buy a metric shit-tonne of pretzels, but Costco has decided that they're not going to carry pretzels. It's not the best.
The products they do have are unusually high quality for a warehouse. If you're willing buy what's available and forgo any sort of customer service whatsoever, you'll get a pretty good price at Costco.
In conclusion, the tire service centre kicks ass, as does the $1.50 hot dog deal. $55/year for those two things? Worth it.