Some things we will contract out (new city electric connection and breaker box, cutting the concrete for egress doors and windows (not installation, just cuts, we'll do the rest) and the rest we plan to do ourselves. 

Josiah - I took a look at your analysis and you might want to consider: expenses for common utilities (i.e. sewer, electric) if there are any, "re-leasing" fees from the management company (I would anticipate 1 or the 4 units needing to be released each year), and then overall maintenance each year - not sure I saw a number for that, but I would think 8-10% is a good start.

Pulled electrical cords from each light sockets.  

It carries the staying power of that more similar to a conventional mortgage, and I don't pay for access to equity until I'm actually ready to use it.

Now this may change with time, and in fact we're already seeing a new build right off of Powers Ferry near Windy Hill Rd, but most large contractors/insitutions are focused on buidling in Midtown given greater demand there.

Here in VT, 50k is not enough to finish 3 rooms and electrical.

One of the largest cost is going to be in bringing the lines (gas/electric/plumbing) over and of course the drains for the waste water. 

Cap Ex: Roof needs redone, and electrical and wiring has newly been done.  

How old is the electric box and roof? 

Right now you definitely have the power to wait and probably get a better offer, but in the future if the market flips I’d also rather be know for being the best builder/flipper to work with.