A refurb non matching non-transitional 1950 sks is relatively easy to come by. If you are really stuck on selling one, that's the one to chop. As has been mentioned, a new military chinese is harder to find and prices are rising based on the supply/demand. In a few years, folks might be saying "I remember a time when they were only $300".
You don't sound like a collector, so I suggest keep and shoot them both, put a peep sight on one and a scope on the other, so they have different purposes. What if you want to go shoot your sks with a friend and end up having to watch each other? Then you may be thinking "I should have kept the other one, this sucks". Plus, if you shoot and take good care of them, you'll get the best value from them and its likely their value won't change a bunch in the process.
People buy a military chinese sks to shoot it, so it stands to reason the fired/unfired condition won't affect the value to those people.
You don't sound like a collector, so I suggest keep and shoot them both, put a peep sight on one and a scope on the other, so they have different purposes. What if you want to go shoot your sks with a friend and end up having to watch each other? Then you may be thinking "I should have kept the other one, this sucks". Plus, if you shoot and take good care of them, you'll get the best value from them and its likely their value won't change a bunch in the process.
People buy a military chinese sks to shoot it, so it stands to reason the fired/unfired condition won't affect the value to those people.