Class C properties are determined by age, quality, work needed, etc, not by price.

The problem with stripping out that sort of plaster and putting in drywall is that the joists of plastered walls, especially pre-1920s with old milled lumber, were never straight and even to begin with, and age and uneven weathering does not help them much.

I also know people with incredible hair and my hairline started receding at the age of 20.

First of all, we live in the information age.   

Hey Ethan, I'd say the BRRRR is the way to go for just about anyone your age (dragging a young family through construction zones could be pretty tough).

You could possibly get a tax advantage by slowly doing a Roth IRA conversion from your 401k, prior to reaching age 70 1/2 when there are Required Minimum Distributions.  

Property taxes are roughly .5% to 1% of the MARKET VALUE depending on the township, age of home, etc.

Based on age you may run into lead as well. 

It does Not cover a roof simply wearing out from age, felt/materials coming apart, etc. 

Great job getting into real estate at a young age!