Cabelas sells double rifles made by Sabatti. I think they start at around 3K. I don't ever recall seeing a good used double for less.
Sabatti production is pretty slow. As such, there aren't very many around, and even fewer showing up on the used market.
Even so....
I've fired 2 Sabattis chambered in .450 Nitro 3.25", and had my hands on several in .45-70 and .470 Nitro. Both of the .450s were a massive disappointment, and the others were not impressive. For $4,500 .... you deserve a lot more rifle, better fit and finish, better reliability, and better service. (Even the $3k "base model" .45-70 isn't what you expect for the price.)
The first .450 I dealt with broke BOTH firing pins in less than 200 rounds. After it was "repaired", it wouldn't lock up correctly. Sabatti (EAA) refused to deal with it; so the rifle had to be repaired locally. Then, it broke another firing pin. When shipped back for the repair, they said they found a safety issue with the rifle and had to send a (new) replacement. Getting that replacement imported into the US took nearly 9 months, though.
When it finally arrived, the second rifle was dragging its firing pins across primers when the action was closed. During its first outing for testing, the rear sight base broke loose. It was shipped back for repairs, and has been acceptable since; but the owner isn't what you would call "happy" with it. He feels like he got a $1,000 rifle for more than 4 times the price, and is just waiting for something else to go wrong.
Unfortunately, I've seen several other reports of similar problems from other owners, as well.
Get the Baikal.
