Shill bidding is obviously more effective with hard to get items, out of stock items, etc, but I wouldn't bid more than it's worth. Atleast, not by much. Maybe 10%, maybe 30%, it depends on the items value. 10.000$ or 10$ will get different % increases for example. My question was directed to the people who bid 500% over, or regret it when they figure out they've been shilled. Like with this auction.

If you bid 1500$ for an E-revo that's worth 500$ in a store to keep up with the other "bidder", then it's nobodies fault but you. You should have stopped at 550$ and just bought it at another store... obviously..