Yep. Sven makes an excellent point.
When you deal on Ebay, people wanna know if you're reliable, and a person of your word...that's why they have a feedback/rating system, which you have to build up.
Here's a little kicker: While Ebay is essentially free, they stick you for 1% of the value of the thing you DID NOT sell, as well as a % of what you did sell.
So what's likely to happen, if you put up a whole buncha expensive stuff, well, nobody has a rating on you yet... so it won't sell, basically. And you'll have to pay (hey, bandwidth ain't free...) .
So I would second what Sven said.
Oh, and they give you one picture for free, so make it a good one.