I'm having a lot of trouble geting my head round this problem. As I posted in my newbie thread, I've just registered DeclinedLoan.com. I looked on Google search trends, and the singular phrase gets twice as many searches as the plural. Buy Domains own the plural, and wants getting on for four grand for the name, but nobody bothered to pick up the dropped singular name. All of the extensions for the plural are registered, but seem to be undeveloped, but the singular name is available in all extensions. (except for the .com of course).
So can someone pick the bones out of that lot, and try to help me put a value on the name.