Whilst it is annoying and we all want a bargain, I don't see how it can be illiegal. No one is forcing you to bid or buy, just set your maximum - some you win, some you don't but nobody has actually robbed you. In other words, if you were prepared to pay £10k and got trotted to £10k, what's the problem. If it was trotted to £10.5k it either doesn't sell or it went to someone who wanted to spend £10.5k in which case you still wouldn't have won.