Depends .
A brand spanking new piedersoli can be had in Canada for 11-12 hundred dollars.
I just so happen to have one for sale in the antique sales for 750 $$
Loyalist makes a really nice longland.. I think a non kit completed one goes for 800-1000
I have one that I bought as a kit from their "specials" section for 500$$ a few years back.
I really took my time finishing her and now I have yet to see a finer repro brown bess, I wouldent sell her for 2000$$.
Beyond the production ones kits can be had from -the rifle shoppe and track of the wolf-
For rifle shoppe kits I have heard you could wait up to a year or more for parts..But you will have a really nice pile of parts to work with.
Im shure whatever bess you pick you will have a hell of a time with it, they are fantastic arms.
..No doubt as they are still to date the longest serving military firearm in human history 1723-1850