RE: cost of muzzle loader shooting
Cost per shot all depends on what type of muzzleloader you plan on shooting. Before you decide on this finally check the game regs in your state and in states you plan to use it in.
If cost per shot is a big concern I would say that a rifle that shoots the patched round ball (PRB) would probably be the cheapest way to go. In order to get a PRB to shoot very accurately you need to get a rifle with a minimum of 1:48 rate of twist in the rifling to shoot great you need to get one with a much slower rate of twist. The 1:48 twist will most likely shoot PRBs fairly well as well as conicals (maxi balls, great plains bullets etc) but will not do very well with the sabotted bullets
To get a rifle to shoot the sabots the rate of twist should be 1:28 or there abouts.
In todays market you have a choice of a flintlock, side lock percussion or an inline. There are a bunch of models of each out there.
If cost is a real factor I would suggest using the loose powder vs the pellets as the pellets are very expensive.