I would like to snipe an item but ONLY if another buyer bids first...an example would help. Some sellers start an item off with a minimum bid of say, $100, but if no no bids come in at the $100 minimum, the sellers will re-list the same item at, say $90 minimum bid. So I would not want myibay to bid at the $100 level unless a last minute bid comes in first, and then I would want myibay to enter the auction. Is it possible to set this up? Thanks

You can't guarantee that another bidder will snipe this item at 1 seconds, and you would not have enough time to react.
Myibidder can't do it, and it also very challenging on technical level.