Yeah, the wear/burn won't be cheap to fix unless you can do it yourself. Just lol at the positioning of the burn though, if the owner was such a keen smoker to not be able to put a cigarette down for long enough to reach into the back for their shopping/coat etc then the car was probably smoked in quite a lot and thus the seats probably smell.
They normally go for £650-850 assuming overall decent to excellent condition.
@dangerous dave I don't know what abuse seats should really expect to get?! Uncomfortable is just an opinion (a wrong one).