I bought an M44 for $75 and a case of surplus ammo. Shot it, realized that Mosin accuracy really was lousy, and dumped it.
Bought a Yugo SKS unfired new in the cosmoline for $100. Bought a case or two of cheap surplus ammo, cleaned it up, refinished the new but almost unsanded stock, shot it, played with the funky grenade cutoff and sights, but realized it was too heavy and too inaccurate. Dumped it.
Bought 3 k31s for $125 each. These, of course, shot well! The fine design and cachet of knowing the soldier to whom they were issued was cool. I bought a bunch of GP-11 and loaded for them, and had fun initially. Interest waned, and in a fit of caliber consolidation I sold them all.
I still have my Garands and M1 Carbines. But the European stuff never really set my Jell-O.
I think that most Americans, unless they are dedicated collectors, don't really take to the stuff that was imported to the US in large quantities unless the guns are functional, useful for field or bench use, prices are really cheap, and surplus ammo is widely available. If those factors aren't there, then prices can't go up that much.
I doubt that Mosin, SKS, and K31 prices will go up much faster than general inflation in the future. Unless there's a ban of some kind, of course .