Selling parts and lack of manners.

Being in a checkout line at a store is not the same. People in line aren't getting up to the cashier and then asking questions to decide if they want to make the purchase or not and they are not calling their spouses to see if it's OK to buy that bag of groceries. They are already committed to the purchase before they even get in line.

With online auctions, ya snooze, ya lose...simple.
I don't see how you can get "screwed" out of anything if you haven't even paid for it.