For e-Auctions including e-Bay:

Bids at the last second to maximize your chance of winning.
Keep your interest in an item private.
Don't commit to buying one of a number of similar items (other bids can be automatically cancelled once a bid is successful).

You will win more eBay auctions.

If you buy any of the robots above after checking them out, I will get a commission on that sale. The commission is built into the price and you will pay the same price wherever you buy.

If you do try any out, remember to use a demo account first and, please share your findings, good or bad.