I would say take a look at the wear on the parts. Little wear means little risk. All GI parts are an absolute bonus, though you would only be able to tell that the bolt, operating rod, trigger group are GI because they are stamped.
For $900.00, you get a complete rifle?!. Stock, barrel, sights, action, etc.
How about telling me where that pawn shop is to I can drive up there and get it before you figure out what the cost of the parts alone are.
If I'm not shooting, I'm reloading.