The no hassle returns from Amazon mitigate everything. I recently bought direct from someone and had to return because they didn't send the advertised item. I had to pay return shipping and a restocking fee, costing me $40 and a lot of my time. I tried to work it out with the seller not realizing that I only had 30 days to dispute with Paypal, so I was screwed there. My overwhelming takeaway was I should have bought from Amazon. (and, if you use paypal open a case with them asap instead of talking to the seller first).

I don't particularly like Amazon and would like to shop somewhere else, but it is sooooo convenient that it's hard to quit.