.- Experience: You’ve successfully navigated a purchase, rehab, and refinance, which are the core components of BRRRR.Considerations: - Budget Overrun: Being $27K over budget highlights the importance of tighter cost estimates and contingencies.

Getting some firmer estimates tomorrow! 

You have to try to estimate MTR income in your area + take into account the costs associated with MTR setup.

What did you estimate for maintenance/cap ex for the 2 units and how did you derive the number?

From what we can find, houses with piers in the neighborhood have largely had to go very deep (90-120 ft), so estimates from local foundation contractors are ranging from 70-130k.  

Estimated cost for remaining changes (all new electric, drywall, tile, fixtures, cabinets, roof, doors, windows, heat pump, some siding, and fencing.

Banks must approve a short sale for a short sale to take place, and banks hire appraisers and other real estate agents to perform broker price opinions (BPOs), or estimated values of the home.The goal would be to negotiate with the seller before the home becomes a short sale. 

First, estimate what the renovation would cost, how long it would take, and how much extra you could potentially sell the property for once it’s fixed up.

Roughly, I estimate I can sell the California condo for around $600, then 1031 that into condos/townhomes priced at about $250k.

Unless you are confident in estimating the renovations needed, I would highly recommend getting a contractor's professional opinion of the rehab costs.