I think the SRP was around 600.00 20 years ago. I only have seen one at a gun show lately, thinking the asking price was mid 400.00 range. Exterior looked good, never checked the barrel. Don't know if he sold it or not.
I have two Hatfields, a .45 flintlock manufactured in 1989 by Pedersoli under contract with the U.S. Hatfield company (using L&R Locks and premium maple from the US), and a .50 caplock by the original Hatfield company in St. Joseph, MO. If you offered me $600 for each one you would not get either one.