I think one of the best ways to support a lower valuation for your prize is to use a "miles" contest that has a lower valuation per mile...something like this one I posted almost 3 years ago:

http://svc.travelocity.com/promos/mi...LOCITY,00.html

If you click on the rules, you'll see under "Prize Details" that the ARV is $10,000 for one million miles (any airline) - $0.01/mile.

I don't know if this one is too old to help (the contest ended 3/14/02), but if you can find a newer miles contest with a similar valuation, that may be all you need.