I buy stuff from amazon usually over other places as they're usually cheaper, have free shipping, and an easier return process. I haven't yet received any used, damaged, or otherwise not as described items, but Iv heard from friends who have. I usually only buy if its sold & shipped from amazon though I know it could still happen.
Unless its something I need right away, I always put things on my wish list and wait for the email of the price drop lol. I did wonder why the prices on some things seem to change daily, but I see now.
The only thing that's happened so far for me with amazon is when i got an email saying I was just refunded and that they received the item back...I hadn't put in for a return on that item, but I was going to that week...I was going to bring it up to them but decided to just keep the refund and give away the shifters instead.