As it clearly has German proof marks, it's not Austrian. There should be more marks under the barrel.
As for value, while you see many of these "liberated" guns with asking prices of $2000, you rarely see sales at that range. If it is in a still available caliber you might see $1500 for it, if it's in some obsolete chambering like 9x57 my guess would around $1200.
F 135 - the right choice