That looks more than "minor" damage, I wouldn't touch it, but that's just my opinion. May have also had water inside which from past experience causes a lot of problems. Good luck!!
From my experience, a repair is necessary when you take a 10kg board for a sail and take home a 20kg board...and need to wait 3 months (after 'venting' the board) until it's back to 10kgs again!
...or when 1 board becomes 2 boards! (done that also).
Definitely needs repair, and if it has been sailed like that it will have water inside and all sorts of deterioration could be going on. Proceed with caution!
Seller specifies it is a Dri-core so if that is true, water will not be an issue - especially if it has been sitting a while so any little bits of water near the surface have evaporated out.
Up there near the nose it is not structural (for normal sailing). But the next hit on the nose will probably snap it clean off unless it is repaired properly. If you can get it for $250 it looks to be an OK deal if you are handy with repairs
I'm with Mark here. I see no sign of a bung, so there is a reasonable chance it's made from closed cell foam and doesn't soak water. But the nose has been hit hard, probably by the mast, and reduced it's strength considerably. You wouldn't want to hit it in the same place again. Also at speed if water gets under the sandwich it can start peeling it off, definitely needs to be fixed.
