Some quick points..
That Sistema isn't a Colt contract gun; it's an Argentine-made gun, using Colt's tooling, with local labor. Dunno about unissued, either..I can see some buffing evidence; it almost looks as if it was refinished. Could be wrong on that, though
But, yah. It's only inherent value is as a shooter, and a fantastic platform to start a build on. Prices on 'em are going up, too...
It also depends on what you're going to do with it. Are you going to shoot the wee out of it, send it to Yost or another qualified smith, get it worked up, etc? Or are you going to shoot the wee out of it, and keep it original? Or, are you going to just keep it in your collection?
For option A, get both, use the Sistema.
For option B, get both, use the Sistema.
For option C, get both, and use the Sistema.
But, if for some strange cosmic reason, you were limited to just one? Jump on the Rand.
Also, check to make sure it really is a RR frame. I've seen quite a few hump-ups over the years that had things like Colt frames with RR slides, etc. Actually saw someone try to pass off a Colt frame with a Singer slide, as a Singer...that one made me cringe. At least I got the slide, though