Are you able to do any of the finishing work yourself?? You usually can save a couple of hundred dollars on the cost of the gun if you do the final shaping and finishing. Talk to Tony Avant, at TVMuzzleloading, and Dick Greensides at Pecatonica, and Tip Curtiss, and to the builders who regularly join in on discussions on this forum. If you are willing to settle for a "plain Jane" fowler, and are not worried about being Historically correct to some museum piece, you can get the cost down to $1,000, and sometimes less. I didn't want a patchbox on my gun, and that save a bunch of money, for instance. I was willing to do the browning of parts, and the finishing of the stock, and that also saved a bundle. I am working on a parts guns now, where I have to do the LOP, and fit the buttplate, and the trigger guard, and pipes, but I had the barrel and lock inletted to the stock. I will have to do the sights, and finally shaping and sanding before staining and finishing the stock, but I can do those things. I have the option, if I decide to change my mind, of putting a wooden patchbox on this new rifle, but my inclination is Not to do so, right now. Perhaps after I get everything on the stock, I will change my mind.
Mike's Tutorial, on the Gunbuilders post here, gives excellent information on how to go about working on various aspects of the rifle. If you have not studied it at length, you should. You might surprise yourself by what you find you can do, so you can get that Heirloom( or 2) sooner.