rarer, yes, valauble, not really. Value wise / cost wise, nazi era guns, then imperial, then weimar (double date falls in here), then weimar commerical, i.e. 1920 commerical guns.
Then of course, condition is everything, as is originality. If it lacks those, the price drops... If looking for a good shooter, find a mismatch for around $500-$600 and shoot the heck out of her.