Slowly build out a repeatable process...if you continue to change things (as in different types of properties, different levels of renovation, different finish material, different neighborhoods, etc.) you create more variables and make it harder to solve to the problem.I am a math guy and less unknowns/variables you have the easier the problem will be to solve. 

Since the owner needs to pay your attorneys fees (essentially limited by statute, so can be estimated) in connection with a redemption, all of that math should be part of the planning.

That said, I have a nice stream of passive income (including math freelance jobs to keep me busy), and a lot of time on my hands, as well as experience with materials and vendors doing home renovations.

Just for simple math use average 20% personal tax rate.  

When looking back, that isn't an accurate way to do it for a variety of reasons, plus it is a hassle every time to do the math and collect.  

I don't know about your idea of maths but to me that says Midwest performs at 2X of CA. 

Timing for permits: every city is different and if you will use this strategy then you have to do your homework and look for cities where permits will be less than 3 months so that it doesn't take you 1 year to build. 

We're not curing cancer; it's just buying real estate, doing some basic math, buying some furniture and kitchen utensils, maybe getting creative with some amenities, and listing properties on STR platforms...it's daunting when you're new, certainly a grind to get started, but it's not a mystery or puzzle to solve.

My fast math, is I can invest in 350 unit apartment complex.

Prices are high, and rental income usually doesn’t make the math work.