I don't reckon it's shill bidding - not enough bids. Moreover, the winning bid is a snipe in the last few seconds of the auction. The relatively high bid for what looks like junk, maybe because it's thought to be a rare die pairing. I'm not 100% sure what the pairing actually is, because the coin is so worn. Pretty sure it's reverse D, but although the obverse doesn't look like 6, there isn't any obvious cut out at the base of the bust, present on all other 1861 obverses with or without an L C WYON, but the lack of which, distinctly hallmarks a 6. So not certain. Hopefully someone else can help. Don't think it can be obverse 6 as the spacing of the letters in Victoria is closer than a 6, and the top of the head isn't as close to the rim as it would be with a 6.