That all depends on the builder & his prices, & what the rifle specs are, wood, barrel, lock, etc. Rifles I build all start at $ 1450. and go up from there. The min. price being a standard rifle with good wood (not the plain low end but a decent piece of wood) and a swamped barrel & Chambers Siler os Siler lock & etc., Davis single or double set triggers, brass or iron trim.
IMHO, any builder worth his salt will have a backlog. If he don't have a back log, I would sure be uneasy as to why he don't have one.........
If my work should interest you, you can look at some of it at my web site.
http://www.custommuzzleloaders.com and I would most happy to talk to you about one. Terms are negotiable most of the time. References available upon request.
As said on here before, you can go to TOW site & see lots of rifles, just remember they are marked up about 30-35% so if you find one from an individual it will could be priced lower.
Also, TVM sells some nice semi-custom rifles & they are a decent price for what ya get. If you are close to Friendship in June, there are lots of dealers there with built rifles priced decently, and some nice ones. Not custom made for you, but you very well could find one that fits you quite well.
If you are within a days drive of Nashville TN, just north of there is Tip Curtis Frontier Shop & he will have some rifles in your range or possibly a "In the White" rifle that you just have to finish... He is in Cross Plains TN, and his tel# 615-654-4445 I would call before I go as to be sure he will be there. Well worth the trip as he has a boatload of parts & will most likely have 20-40 rifles built.
Hope ya find what you are looking for..
Birddog6