It really depends. And don't panic, 'cause the stuff really isn't that spendy.
How exposed is your dry wall? If it's smoothed over and just not painted, then you're right, all you have to do is prime it.
But if you've got seams showing, you need to cover those.
The seams were sealed, but the seal is a little rough. We were going to just sand 'em down and spackle. But the corners are...empty. If that makes sense.
We're down to that brown paper stuff on the sections, and they're in good shape.