I know its not er.. "period" to have a a rubber butt pad.. but if you get into shooting heavy loads the typical curved brass butt plate will leave you bruised and confused.
If you are just target shooting, a 45 or 50 cal rifle is just fine, though around here it seems 45 is harder to find bullets for. 50 and 54 are all the rage here but that's because we have been known to hunt with the old smoke stuffers.
My first rifle was a Thompson/Center kit gun I picked up at a gunshop used for around $200.. probably paid too much butthe stock was pretty and it had a browed instead of blued barrel.. which i thought was nifty.
Anyway, after the rifle there comes buying all the accessories that go with it. Power, bullets, caps, cleaning jags, bullet pullers, barrel lighrts, solvents, ball butter, lubed patches, a box to store all the stuff in, a possibles bag for hunting, 3 speed loaders, more bullets etc.
And that's not even counting the burning desire to purchase buckskins and a tomahawk.
Seriously, you can spend almost as much on needed accessories for a muzzle loader as you can on a first rifle.
If I had it to do over again I had passed on a TC "patriot", a 54 cal half round/half octagon 54 with a nice pistol-gripped stock and sling swivels that I thought cost too much at $275.. after bruising the crap out of my shoulder I wished I had got the patriot.
Another rifle I looked at closely was a 58 cal Enfield Musketoon, a shorter, lighter carbine version of a CSA rifle. Pedersoli makes the one I was interested in and I let the sales guy talk me out of it.. mainly I wanted a hunting rifle, not a reinactor's prop.. and to be fair, the sights were a bit crude. Still after lugging a 12 pound hawken all day I wished like hell I had bought the Musketoon.
I still have the hawken, but I still have my eyes peeled for a TC patriot, or a musketoon with blackened furniture.