I can't be bothered going to costco even though it's only a 10 minute drive away for me.
I have a coles & Aldi at the shopping centre near me so I just go there. Buy some things at Aldi & the rest at coles. I just stock up on things when they come on special at coles.
I have seen on TV & read in the papers about people going to Costco & have spent $300 to $700 in one go, claiming they saved heaps, but in the end they ended up buying crap they have never bought before just because it was so cheap.