i was told by a Martin collector it was worth ~$20k, but they always insure them for double.It was like 100 years old or so, and was on loan from the Martin museum. I don't think he knew anything about it (or vintage guitars in general), and they had multiple guitars to smash for that scene so he thought it was good to go for what he needed to do.
Don't remember the model or price it was worth, but it is irreplaceable. Big fuck up to destroy a piece of history. I think Martin released a statement after saying that they will no longer loan guitars from their museum for any reason.