Originally Posted by Plumcrazy
...What are the dangers of sailing with it this way in- say 10ft waves?
What you are talking about is failure of the support structure for the mast, so the whole rig could come down with even fatal results. Surviving that you've lost sail power too.
As previously stated, you need to get a professional opinion and estimate involved in this. You need to do that before the transaction proceeds to assess the financial viability including repairs.