Square footage too small?

Their cost per square feet is higher than larger sfh because you don’t have the offset of cheap square footage, hallways, big bedrooms, etc and you still have to have a bathroom and kitchen. 

If I find closer to the 60k range, I will invest another 60-80k adding square footage and making it into a large 3/2.

Your analysis seems to indicate that people are buying for +-70% of MLS sales square footage. 

And insurance companies can usually give you a quote with some basic information on the property (age, square footage, major amenities, etc.).

Adding square footage to your property may not be realistic but there are other things you can do.

Square footage, age, lot size to give a general idea, then you go in and narrow down by finishes, age of mechanicals, school zones and a few other things. 

If you look at most of the new construction that comes on, they will advertise finished basements or third floor bonus rooms in their square footage (and some even garage space).

Total dollars, sq footage, parking, roof, etc.  

-Look at what rent price the houses are listed at for each size and type (SFH 3bed/3bath and sq. footage)2.