I would go to your email inbox. If you haven't received any unsolicited offers for your names then the value is closer to zero than you can imagine. If you have received some inquiries and offers for your names then just add those numbers up.
If you are thinking about paying for an appraisal then zero is probably the number. If you want to send me $500 we'll call it even, and it will save you the false hope and eventual embarrassment that comes with a paid appraisal.
On second thoughts....just save your money and run the names through a few OFFERS threads on this forum. You will have an answer very soon.