Of course you are. It's part of the Costco Experience. But you still get a fair deal on their products in general, and many times there are insane deals on lots of stuff.
The price of a Costco membership is no big deal if you shop there enough. We been doing the Business Executive membership at Costco for close to 30 years. 2% kickback at the end of the membership year, plus 4% for purchasing Costco's gasoline. We shop there about 1 - 2 times a month and spend about $200-$400 each trip. Add a $100 for gasoline. At our level of spending, the "Rewards" kickback pays for the membership plus an average of $250 that we can use as cash or store credit.
Costco is a very impressive business model that includes taking care of their employees very well too.
Yes, I love Costco...