Where can I go to get the value of some old Silver Dollar coins?

They are fakes from China. No one pays a bill with a real 1799 dollar not even a fool. There have been so many fake 17799 dollars to enter this country that I would never buy one unless authenticated and neither would any collector or dealer. there have been no new discoveries of 1799 dollars for a good many years. If one is an 1804 it too tells ne they are fake. Morgan dollars started in 1879 but if they were mixed in they too are doubtful in the real department. If the 1799 and if you have an 1804 and they have reeded edges then there is no question for the real coins have lettered edges. Usually a coin has to be seen and examined by hand but some of the fakes can be told just by a good high quality photo. I allow email through yahoo answers and if you do that I will send my email address to send them or scans. If not see if a coin club is in your area the members would be glad to help. Try at least 2 coin dealers. Sorry for the bad news and they are not made of silver, the 1799 should weigh 29.26 grams Morgans which have a bust of liberty and an eagle on the reverse with spread wings should weigh 26.73 grams.