Ya 300 is a little high 225-250 maybe if it's in really good shape, the bore for that money should shine with out blemish. And is does depend on the region, east of the Mississippi seems to have a lower price than in some western states, it's matter of common availablity or not.
I had one with intent to use on clays and the 28 proved just a little lame, it broke birds but didn't bust'm. But bunny's don't take much to knock'm over.
And un-rifled bore is accurate to 50 maybe 75 yrds with a round ball, good thing with the Renegade is you can find rifled barrels in 50 and 54 that will drop right on (frequently on ebay)
Then you'll need over powder wad, shot cushin and over shot card another $20-30 by the time you done with shipping. Then of course all the goodies that are needed for the ML gun, powder, caps, cleaning jags, capper (shot is $40 for 25#'s)
The Renegade IS a good starter gun, T/C offers a lifetime warrenty and honors that for folks that are not the original owner. There are several models, a double trigger, a single trigger, with a rubber butt plate, with a steel but plate,,
There is a learning curve, esp with the shotgun as powder charge and shot weight variables are what's used to change the shot pattern