Personally I am going to lean towards the K31 as they are fantastic pieces of work, but if your concern is range time and the budget is a bit tight then Mosin Nagant all the way (personally at the moment my K31 comes out every second or third trip, well my Mosins tend to have at least one sneak in to the firing line).
A heads up with the SVT-40 is that it can be very picky ammo wise, it took 3 different types of milsurp ammo to find one my rifle liked (tons of ammo for my Mosins though). Unfortunately I ran out of the type it liked, so now I am searching again as otherwise I will have to buy modern ammo, and the way it treats brass, that isn't too affordable.
My recommendation would be get a Mosin Nagant, with a crate of ammo, and a .22 plinker of some sort. I know a .22 isn't what most want to hear (it took me about 15 full power rifles before I bought one) but ammo wise it can save you a ton.
At the end of the day get what you want, I bought a SKS first, followed by a Mosin Nagant 91/30 followed by a SVT-40 (before all the recent imports came in so the prices were higher), don't buy one because you expect to make a profit, buy one because you want one.