I only wear clothes approved by the Kardashians...
Just kidding!
I like Costco, I even suprised myself one day when I relaized almost everything I was wearing was from there.
They have the best white t-shirts and free food samples to boot.
Outside of that my wife does most of my shopping and I'm not sure where she goes. I'm pretty sure she is spending more than I would.
I haven't bought anything much from ebay a couple bike parts and years ago i bought some computer stuff.
Friend of mine I work with seems to have good luck there though.