Heshy: Have you ever shopped at Costco? If not, I suggest that you ask a friend with a membership to take you. You can browse around and then decide if it is right for you. If you live in a large centre with a large Jewish population, then generally Costco carries a lot of kosher food. My daughter buys most of her meat at Costco and says that she saves a lot of money – often paying the same price for kosher chicken as treif costs. She also gets a lot of Shick bakery products in large containers at small prices. Where I live, the Jewish population is small and Costco does not carry meat. In fact, the only time they carry specifically kosher food is at Pesach when have Kedem grape juice, large boxes of matzo and macaroons in big jars. But, of course, a lot of what they carry happens to be kosher – nowhere can you get pickled herring for such a low price and here, they do have the lowest prescription prices in town.
Basically, you have to weigh all the options and decide.