Yah, the wood makes them a bit more work to do, so rehabb and flip is a bit more dicey. But a buyer might pay a premium for some nice new looking wood. Check the firebox for holes, especially under where the flavorizer bars rest. Check the front top edge of the fire box for bowing out. If it is too bad, grates might not fit well. Check the left cross member on the frame for excessive rust where it bolts to the firebox. Those are your big issues. If you can find the side table that is missing, that would be great, otherwise you would need two Z bars after you make new slats for it. If the tank is included. that would be a bonus.
$40 is about as much as I would pay for one of those though. They are not real hard to come by around here.