I personally love costco, but I am curious about all the posts about their meat department being cheaper than the grocery store. What grocery stores are you going to? I'm in central PA and meat/seafood are about the only things I wouldn't try to get at costco first since they always cost more there. I agree that the prices suck at the big chains like Giant, Safeway, Wegmans, etc... but all the single store and local chains around here blow Costco and the big chains away in price and service. Costco's quality on their meat/seafood has always seemed excellent, better than the big chains though no better then the local stores I go to. Maybe it is just around here, but if you think Costco's meat prices are good, you might want to check an actual butcher shop or 2.
Its probably quite regional. I can get filet mignon for $9.99 at my costco and rib eye often drops below $7 a pound. At the el-cheapo stores like Winco and Food4Less, I could approach these prices but the quality is absolutely not even close. At the regular chain supermarkets, the prices are from 20-30% up to 50% and more higher. I can get wild salmon at Costco for under $10 a pound and scallops are in the same price range per pound.. I can't touch that at any other store.
Butcher shops? Ehhh...generally almost double the price of the chain markets. Quality is great if you're going for prime convenience cuts, but I'd rather eat four pretty good steaks instead of one really good one. And if I want really good, the prime beef at Costco is much, much cheaper than prime beef anywhere I can drive to.
I'm sure if you live within 20 miles of a major cattle processing town, the beef prices are probably favorable towards small independent shops and local chains. I do live in the middle of such an area, but the Costco beef and seafood prices near me are unparalleled by markets.
Freshness is also a factor. Costco turns their food faster than just about anyone. I've never had a problem with picking up a package of meat or seafood and seeing it was expired or about to expire. I can't really say that for the local markets. Quite a bit of what I pick up there is near or past its expiry.