US army Retired,
Take the good advice from Allen. Visit Dixon and maybe one or two other Gunmakers shows. Do you just want to shoot, reenact, hunt or a combination of it all. If reenacting, how early is your history start. A good "Rule of Thumb" for it is; if the style existed in that time it fits. a half stock Hawken wasn't in the Rev War period, it's wrong; But the Early Lancaster may have been passed in a family & is around as late as the early Fur Trade, passable. Visit a Library for a few hours some free night and look at books with pictures of on these firearms. Take time at home to search you minds eye and figure what you want to be, represent, have. Get YOUR head straight as to what tickles your desire and need.
Buying a custom firearm is like getting your desired auto. Basic, Add AC, GPS, Backup camera, proximity warning buzzers, fog lights, power seats & windows & door locks etc.etc.etc. It all adds to the total; But also to the ultimate value. YOU GET WHAT YOU PAY FOR. Your firearm adds are, but not limited too: plain or fancy and how detailed, incised carving, relief carving, or combo of both; same on the metal parts; inlaid with Steel,brass, silver, German silver and plain, carved either way etc. The choices are endless. Don't let a high dollar cost scare you off, it's also going to APPRECIATE in value over time. Just don't abuse it. They are made to be used. Until you build a gun from parts or scratch, your knowledge of what goes into it is limited. I do guns for myself and may sell it after years of having and I decide it's time to make another. I have an Early Lancaster in the white. I'm deciding whether to leave it as is and finish it plain; Or, do light incise or more tedious relief carving. I have fancy and am leaning toward plain. But these are mine, for me. Here's the pic of the in white, and others I've done: