Most appraisals aren't worth the price.
A cheap quickie appraisal: See what BuyDomains has priced for sale that's in the same league as your domain(s). See what similar domains have sold for by reading DNJournal. Post the domains in the "make offer" section of any domain forum that allows you to post domains for sale.
Ask 10 seasoned domainers for a valuation and you will get 10 values.
Look out for those who want to price your domains based upon any PPC revenue they produce. That's a rather 'thin' valuation model in my book.
You might also scan the library here, in the Domain Forum, for some tips and insights on appraisals.
The problem with asking me for an appraisal is that I'm just one point of view. I may or may not have expertise in the specific realm the domains target. Even if I do the values tend to be all over the place as you are likely hoping to find end-users who will pay the highest prices (not domain resellers, etc.).