All dependant on that rust on the arch really. The graze on the bumper and dent on the bonnet can be sorted easily enough in time. You can source a new horn button I'm sure and OEM rear lights are plentiful on ebay (although those are probably the best looking lexarse lights you'll ever see on a lude

). So if that rust really is minimal and something you can easily sort/stop yourself, then you'll be good to pay up to around the £1300-£1400 I'd say.
Your bartering can use the fact that you will eventually need to get that bumper and both rear-quarters (if it is both arches) resprayed as it's a metallic paint, so won't blend well. That
could easily cost over £500-£1000
