Hippy,
Mate as far as I know (my wife is in the legal field) a deposit is a legally binding arrangement between a buyer and seller.....esp. if there is signed paperwork involved. If the buyer never comes back the seller keeps the deposit (compensation for turning people down) and in turn if the seller sells the item to someone else after you have put a deposit down, the seller is legally obligated to provide you with the same item at the same cost as what was agreed to.