Hey David -
A good source of less-expensive starter bp rifles is the Black Powder section on gunbroker:
http://www.gunbroker.com/Auction/Browse.asp?Cat=2324I have bought quite a few through that site and most have been pretty good transactions. There is always the occasional scoundrel, but I think that happens anywhere.
Here are a few current listings that would be good to get started:
http://www.gunbroker.com/Auction/ViewItem.asp?Item=144842974http://www.gunbroker.com/Auction/ViewItem.asp?Item=144838386http://www.gunbroker.com/Auction/ViewItem.asp?Item=144638503http://www.gunbroker.com/Auction/ViewItem.asp?Item=144186971http://www.gunbroker.com/Auction/ViewItem.asp?Item=144206615More expensive, but nicer:
http://www.gunbroker.com/Auction/ViewItem.asp?Item=144197336http://www.gunbroker.com/Auction/ViewItem.asp?Item=144752058Keep in mind that the Lyman Great Plains rifles work great with round ball (what you use at rendezvous), but the Lyman Great Plains Hunters are made for conicals (more for hunting).
There are is also a blackpowder section on
Auction Arms, but I've had less experience with their site/community.
If you are newer to the hobby, I would recommend not spending a ton of money on a rifle or gear, as your persona is bound to evolve. Start with a less-expensive rifle (that works well and isn't frustrating to use) and then start asking around the shoots about other people's guns that interest you. For example, you may start off thinking you want to be a Mountain Man from the Western Fur Trade and then decide you prefer the Eastern Longhunter look - which is a pretty different style of rifle.
Take care,
Many Rifles
Many Riflesmanyrifles@gmail.com"Full time night woman? I never could find no tracks on a woman's heart. I packed me a squaw for ten year, Pilgrim . . . I lodge-poled her at Deadwood Creek, and traded her for a Hawken gun." - Bear Claw Chris Lapp,
Jeremiah Johnsonhttp://www.buckskinning.org