I don't use bots, but I learned a long time ago that sniping is the only way to go with eBay auctions.
It's like, I would see something I want, and say "I'd pay $20 for that" and put down my bid, and it says that I'll get it for five cents if nobody else is interested. Then a day later some guy comes along and says "I'll pay fifty cents for that" and drops in a worthless fifty cent bid. But they don't win, because my bid was $20. And then that same person comes back in five minutes later and bids a dollar, because that's what it's worth to them now that they've seen that their fifty cent bid didn't beat my $20. No good? Five minutes later they bid $2. They reconsider $5. $7? Ten dollars, ten dollars must be enough. Fifteen? Twenty? There we go. They just saw that I'm in for $20, because my winning bid won't go higher. Twenty one dollars. Ha ha ha, they sure showed me. I snipe at the last minute with $30 (because now I'm a little pissed off and emotionally invested), and yeah, they just pushed it up to $21 and stopped there.
Putting $20 down early was a mistake. I tipped my hand. I let someone who thought it was worth less than a dollar and who had all the time in the world poke me and poke me until they knew exactly how badly I wanted it, and reading my intentions taught them more about what the actual value of the thing was worth. And that sort of thing wasn't a rare occurrence, it happened all the damn time until sniping became my only method of bidding.
The best thing to do is consider how much you're actually willing to pay for it, wait until the last ten seconds, and then put down your $20 bid. If you win, you win, if you don't win, you don't win. I don't think bots do much good except they make it so you can't miss your bid by forgetting to place it.
