Bill, you don't say in your post if you are interested in selling the rifle, or just looking for "what it's worth" for your own information, insurance, etc.
Here's some things that can effect the fair price of a rifle:
Caliber..??? Who made the lock..?? Who made the barrel..?? L.O.P. ?? What finish is on the barrel (pics will be necessary to see how well it was executed)..?? How well were the sights installed ( again pics if you please)..??
Last September at Friendship I passed on a rifle that was ALMOST exactly what I was looking for because the builder had totally cobbled up the dovetails and tried to make up the difference by pounding the metal edges down to secure the sights. What he did went waaayyy beyond "Stippling"..and left a visible gap between the base of the sight and the barrel beneath it. I've looked at rifles where the lock bolt wasn't lined up to go straight through the stock. One in particular...was at a pretty extreme angle so that the head of the bolt was "crooked" when drawn up to the sideplate. How are the barrel tenons done, and how well are they executed ?
Your rifle has a great piece of wood, that's for sure but that won't outweigh poor building. I can take $1000.00 worth of parts plus exhibition grade wood and build a $500.00 rifle which is why I don't try my hand at building from a kit. Eric's WAG is most likely a good ballpark, if the rifle has been well built, was cleaned properly after you fired those 25 rounds through it and is in overall pristine condition..inside and out.