Overheated and the died, coolant boiled. Engine not seized but won't run. RAC man said it's almost certainly a blown head gasket.
I don't have the tools or the skill to tackle this myself, so I had it dropped off at my local garage. They say it'll cost £500 - £600 to repair and they won't know the full extent of the damage until they take it apart. And of course, by letting them do that, I'll be committing to pay them.

Are they taking the p*ss, or is that a reasonable price? (They're not known for being rip-off merchants actually, they have quite a good rep around here).
It's a 1.6 Diesel by the way. Perhaps I should consider upgrading to a bigger engine instead of letting them repair that one? (1Y or AAZ perhaps!)
Any thoughts from any of you technically minded folks would be appreciated.
Cheers.
Adam.