I do not see anything wrong with bids placed on this item. Person #21 had placed 2 bids on item before you placed your bid. When you placed your bid they then started placing bids in small amounts to try and win item. I do not think they were trying to run up the amount you paid for lot. One of the ways of running up the price of an item on ebay now ( usually higher priced items with several bids early ) is for someone to bid a ridiculous amount to see what previous high bidders maximum bid amount is and then go in and cancel bid due to entering wrong amount. Example : current bid showing is $75.00 and you know bid will reach at least $250.00 so you place a $800.00 bid. Ebay will show your bid one increment higher that next highest bidder, so now you will know how much their max bid is. You then go in and cancel your bid as entering wrong amount and re-enter $80.00 so ebay does not get wise. Lets say other person has a max bid of $225.00 that you found out about. What you do with that information depends on if you are a shill bidder or a regular bidder trying to win lot.
A shill bidder not trying to win lot will wait till a few seconds until end of auction and bid $2.00 under $225.00 so other person will pay max for lot. A bidder trying to win lot will bid a couple dollars over $225.00 since he knows max amount of other bidder. I think there is a 2 hour bid retraction time limit before auction ending. There are several other " tells " about Ebay bidding that I will not get into. My best Ebay tip on bidding is wait until last 20 seconds or less before you place your bid.
Looking back at your ashtray bidding example you placed your bid several minutes before end of auction and this gave bidder " 21 " several minutes to push your bid from $10.50 to $33.00 a couple bucks at a time. Had you placed your bid in last few seconds it would have saved you over $20.00 as Bidder " 21 " would not have had time to enter another bid. I hope some of this was helpful.