Ebay doesn't care about shill bidding. I had a bid on a Jnat from a russian seller and was below the winning bid. While sitting eating lunch I got an email that I won the auction, surprised I looked and saw that the leading bidder was cancelled. I started following the guys auctions and you could immediately see the pattern, 2 bidders running the bids and then being cancelled a minute or so before the auction ended. I called Ebay and they said it's difficult to prove, we are investigating, dont pay. Few days later I get an email saying, you didnt pay for your item. When I called I was told I won the item and should pay for it otherwise I would be violating the rules
I eventually wrote a bad review and the guy returned my money.