These are pretty easy to fix and if you get both fixed selling one would easily pay for the whole purchase. Just something to keep in mind that buying untested as-is can be a decent option with the 2nd model. The original model though has a belt inside and a lot more moving parts in general and I would not recommend buying one of those as-is unless you are really handy.
I've "fixed" a lot of them over the years often times just cleaning the lens and greasing the gears but sometimes popping in a new replacement lens. You can always ask them for more pictures of the inside/the board to make sure nothing looks blown out or other obvious bad damage.