Stabilizer link replacement cost

Hi guys. Just looking for some advice as I'm looking to purchase the vehicle listed above. The seller has told me the stabilizer link on the front right wheel needs to be replaced and the vehicle was purchased with this issue. Apparently caused by the larger diameter rims on the car.

I've done a little bit of research on this and it seems as though the part is quite cheap. But that's as far as I've gone.

When driving, it drives really well but there is a slight knock sort of sound going over certain bumps.

Just wondering how bad can this problem get as they said they've been driving with it for a while? And how much would it generally be to fix?