Subdividing two properties on one lot and selling them separately

[Sean Connolly]

I own a 3 Family property. On 1.4acres, there is one Duplex ( 2 1BR, 1BA) and a single family ( 3BR, 1BA) I bought the property for 315K. I have 305K left. I have seriously been considering subdividing the two houses. They currently share a well and septic. Both well and septic are on the duplex side, so I will have to put the new ones on the single family. The single family and one of the duplex units also share a driveway.

I was thinking, Put a new septic (15-20K), new well ( 5-10K) and redo driveway (10k???)

Ballpark quoted on $2000 for land surveying, fees, plans, and hand-ins to the town planning board.

A Duplex can go anywhere from 270-300K, and a single family can go for 230-270.

If my math is correct, am I really going to make possible over 100K for this deal? Or am I missing something big here? The pessimistic part of me is telling me its too good to be true.