I've used eBay a few times a year for a long time. I stopped selling but will buy things I can't find anywhere else. I did like
@RicinYakima did with the bank account and only keep enough in it to keep it open. Then, I transfer money into it when I get the bill - minutes before I pay the bill.
Funny thing is that I only recently got taken. Stupidest thing - I have several jackets ("sport coats"?) I wear at school - all nicer than I could afford, but I got them at Goodwill for less than it cost to have them cleaned. Regular hangers mess up the shoulders, so I wanted some better wooden hangers. Looked and looked.....
FINALLY, found some on eBay and ordered them, got a shipping notification and the first leg of the tracking from USPS. Then,..... nothing. Well, that's EXACTLY how USPS has been working for the past year, but I went to contact the seller anyway and that seller did not exist anymore!
I contacted eBay via their dispute process (easy) and was informed "it woiuld be a few weeks and then,... and then,...." but in a couiple days, I got an e-mail saying I'd get a refund because there was no "real" tracking info., which was werid, because the notification took me right to USPS's site. All the same, I was shocked at how fast they were to put the brakes on that transaction and refund my money. NO hassles for me - they handle the phantom seller or suck it up - but either way, it was no trouble for me other than submitting the complaint.
There are things I don't like about eBay and PayPal, but sometimes, there's just no other way to get some things.
Now, Amazon? I won't even start on that mess. I despise that company more than any I can think of.