The term shill bidding, sometimes with only one l, is defined as somebody who bids on their own goods and/or services being auctioned in an attempt to drive up the price. It's forbidden on eBay, and is even illegal in many areas. That doesn't always deter people and/or organizations from doing it, but when they get caught here's a good example of what can happen:
"An American jewellery firm EMH Group was fined $400,000 by the New York state attorney general’s office for allegedly bidding in its own auctions on eBay.com to increase the prices by some 20 per cent, according to media reports."
In addition to the fine the company has been banned from all forms of online auctioning for a period of 4 years.