I've been on eBay over 10 years now. I've had a few idiots - not wanting to pay of selling items as mint when they are well used - but they are definitely in the minority.

If you are a seller, always make your auctions private so that others can't see who is bidding; only accept paypal and always get a signature on delivery.

There is some terribly overpriced stuff on eBay but there is also the occasional deal.

Just be cautious and as Knifeguy says, look at feedback and how much care the lister takes in describing the item and showing multiple images.