You can configure your listings to have "immediate payment required" added. That way, until your item is paid for, the listing stays up for anyone else. You can also tweak your listing settings so that those with unpaid item strikes cannot bid or purchase, you can regulate those with low or no feedback, etc. Might be an idea, just to weed out those who treat it as a lark.
Rick
"Egotism is the anesthetic that dulls the pain of stupidity" - Frank Leahy