Any one UK a Costco Member ?

Ive had a Costco card for a few years now, a personal family membership not the business one so I can only go after midday, got it through my Dad who's eligible. Just wondered I know its called Costco Wholesale, but is it really a wholesaler ? ie the stuff there is a bit cheaper than most shops and you can buy stuff in bulk, but it doesn't seem cheap enough to buy and sell on, which is what I presumed a wholesaler is.