More than 1 account on Ebay

I have a question that was actually triggered by the tracking cards post earlier. Do you have or think it is okay to use more than one account on Ebay. I have on many occasions with the same seller found that they will list a card and sell it to another account only for it to pop up later under yet another account for more money which is a bit higher than average but somewhat reasonable. There is a sale from the first to the next and then nothing from there to the next but every card they buy ends up mysteriously on the last account for sale within a short time. I asked about this once and the guy told me he had the cards for several yrs. When I told him I found the sale on VCP from 2 weeks prior the guy became irate. No reason for that unless.....................

Could this be a way to defraud Ebay of the Ebay bucks program