Well you're obviously interested in a modern/inline rifle since you also asked about a scope. In which case, I'd agree with @square about the CVA Accura. It's a great rifle.

But if I had $500 to drop on a muzzleloader, I'd mosey over to the classified ad section of https://www.muzzleloadingforum.com and get something more "traditional". There are usually a number of guys selling Lyman GPRs, older CVAs, and similar rifles at great prices. It's also a great resource for TRADITIONAL muzzleloading. They'll run you out of there if you even mention an inline or any type of modern projectile.