No, Ebay does not allow to accept Bitcoin as payment option neither it allows to sell Bitcoins. I tried it myself some time ago and Ebay removed my auction.
A friend told me that it is allow to pay with Bitcoins on Ebay local marketplaces but I have never tried it.
It's cheaper because they offer 15% discount, and you also get some points, nice way to attract people to use their service. I tried to find some info on net how much work they have, and how much profit they made until now but I couldn't find nothing. I was just curious how profitable is to run service like that one.
