Finns
I have been collecting Finns for about 5 years. The M91/24 is one that I have not been able to find for a reasonable price. Someday!
I have 5 M39's. For the most part they all shoot the same no matter what arsenal - generally 2" groups or better at 100 yards. The rarer models would be the SKy, B-barrel, Sneak and Tikka marked ones. There are other variations (straight stock, Postulataitos marked, etc) that collectors strive to get. The most common are the Sako and VKT marked ones. Yes, the Finns are gaining in popularity and the price growth is phenomenal. Rifles that I paid under $100 for 5 years ago such as the M28/30 are now selling for over $400.
If you get a chance to get an earlier Finn such as a M27 or a M28 for under $200, you won't regret getting them. Pretty much all Finns shoot great. A lot of sellers don't know the difference between a Finn and a Soviet rifle and so let these things go for great prices.
My advice would be to go for the Finn in the best condition and not worry about the arsenal.