Each bid costs just 40 pence, and are available in "BidPacks" of 25, 50, 100, 250 and 500 bids.
40p just to place a bid, and you're not guaranteed to get the item... So you place 20 bids on an item and get nothing but an £8 loss.
20 people placing 20 bids = £160 before the item has actually been paid for...