Is it legal to use robot accounts on eBay to raise the price at the auction?

I was bidding on something on eBay, when someone started to tender as well, so I decided to stop bidding for time, and when I returned a few days the price was 600% of what originally was and I checked the bidding history and said the same person kept raising the price after you have left and this seemed to lick his account that were used by aan product.Is seller of this legal to do that?

It is legal to do so at all and against eBay policy. I really hate when they do that too!

Your One Stop eBay Auction Site & Much More