Gut Reno Estimate?

I’m looking to buy a 2 family brick from the early 1900. i was told it will need a TOTAL GUT RENOVATIONS. My broker said it will cost me $100K. The engineer that did the inspection said it would cost at least $250K. A contractor that came for estimate $80K.
This prices are so different. Who is right? Help!!

By artdecopark |