I've only bought from outpost once. I ordered 3 parts, recieved 2, and the 3rd was cancelled (I ordered it when it was on backorder and they were not recieving any more of that component from the manufacturer...nothing they could do about it). They never charged me though. I did order from them again, but cancelled my order (no fault of theirs, I just choose to buy a different part at a different store) I've heard of some ppl haveing a bit of trouble with them, but I've never had any problems whatsoever with the company.
I'd say it's a pretty safe bet buying from them...