I have both Costco and Sams memberships - we like those stores and honestly even if I saved nothing I get entertainment out of going there. Sams is a lot closer so we tend to go there more but Costco is infinitely preferable to us, everything is just that little bit better (and their new very close store will be open in 3 months). Their return policies on electronics will likely get adjusted. I talked to them about laptops a while ago and after learning their policy I asked if they had people abuse it - "oh yeah" with a shake of the head. Considering it's a membership driven store a few bad seeds will ruin it for all of us. No problem with using but a lot of people like to exploit and abuse.
Panasonic 65" VT60 (calibrated by Jeff Meier), Marantz 6005, Kef Q towers/rears Kef Reference center, Win 7 Pro with XBMC, Harmony Ultimate One
Xbox Live: Arbitrage XXL