@Lando
I'm really sorry to hear this has happened to you. I have used Amibench a couple o' times with no probs. I've also sent a cheque in good faith and received the goods fine.
I have actually had more trouble with ebay, even though it is meant to be 'safe' - I'm still chasing someone for over 300 quid, money I really can't afford to lose!
As with anything in life, its always the bad few who 'ck it up for everybody else.
Also, bear in mind that if you have e-mails from the guy that state he will send you the goods, you do, I believe have some grounds for pursuing him through a small claims court in the UK, phone your citizens advice bureau (perhaps e-mail him and threaten him with this, he might not be au fait with the law anyway and get scared and pay up/send you your goods). I would be bloody-minded enough to go after the guy, not for the money but the principle!