Impossible to say without knowing its condition & history. There's plenty of people asking £12k for these but if you look on ebay for completed sales, the only ones actually selling are around £8k.

You didn't answer my original question - who suggested the swap ? I'm guessing you've advertised your car for sale and he's contacted you ? In which case asking you to make a six hour journey is taking the piss. He's effectively the buyer in the transaction, he should come to you. If he was a cash buyer would you make that journey to have a look at the money he was going to give you ????

Oh, and don't get taken in by the wheels and registration and lights being worth xx hundred pounds. They're not. If you like them then regard it as a bonus. If he reckons the reg is worth (say) £1k, tell him to keep it and give you £500 cash in the deal instead. His answer to that will tell you what it's really worth.

Basically, it all sounds a bit dodgy to me. Tread carefully.