Negatives; Mileage obviously. MOT history suggests maintenance lacking. Not one of the more popular / outstanding colours. Damaged seat is glaring and will offput potential purchasers / impact price. Positives; Looks generally sound and has had a lot of recent work done. The 16 valve GTi is very fast. The VW Golf has always been cool, the GTi is über-cool.
It would benefit from a full interior & exterior valet. If you can get the damaged seat(s) repaired / swapped out without major expense it will add value. Servicing / tuning by a reputable outfit would also help to realise best price.
Assuming it drives and rides nicely and isn't displaying any symptoms of advanced engine wear my guesstimate as is, £2½K give or take £500.00. If you could sort out cosmetic issues and have the car driving perfectly it could be a £5K+ car?