If new I'd say it's a good price. If used I'd say a bit high. The lesser caliber ones don't sale as high as the .454 and .480 and the .454 is the highest of them for some reason. I'm trying to sell one of those now for $450 I think is what I've now dropped it down to and still haven't got a buyer. Had a couple of folks wanting to trade but I'm wanting to sell. I'm even tossing in a scope base with it.
No you don't have to buy the Taurus base. B-Square also makes one. Don't think it's any cheaper and not really as good tho.
Ya oughta just buy my .454 and get the scope base free and down load it if you want to shoot less than full house loads.