Somewhere out there, there's a manual written on building a suburban division and in that manual it says "erecting a Costco Wholesale is a must have".
There's a reason why they don't have Costco's in downtown Toronto.. Because city folks don't have enough room in their 500sq ft condo to put all the oversize crap you buy at costos. 48 roll toilet paper, cheese by the kilo, oversize cereal boxes etc.
I love Costco, and could never think of leaving it behind. Everytime you go, it's like an exciting venture, what new thing are they going to have! Any good sales!?!? ohhh ahhhhh...You can find some really good prices, such as on books, cheese, and fruits/veggies and meats... but there are things that you may as well buy at the grocery stores as the savings aren't too big such as bottled water, or canned soup.
Just thought I'd pass on a little costco-dom to you.