Speaking for myself, eBay favors the buyer far too much for my purposes. I've had a few times where I knew the buyer was lying about the condition of the product on arrival, and was just trying to get me to lower the price.
While there are a few things I would consider selling on eBay (CD's, books), things like instruments I wouldn't chance.
I would, however, consider buying something on eBay, including instruments. I also always try to use PayPal......YMMV..