Posted By:
MattI agree Barry - it's not conclusive. It's probably impossible for any user to prove shilling conclusively, and certainly just from the bid amounts it would mean nothing. My suggestion here is based on a confluence of several factors as outlines in the OP.
Tangentially, I will say, that the fact that you can even see that there is another person bidding, and how many other people are bidding against you, is a welcome transparency on ebay, not offered by any traditional auction house.