That has been one of our top draws; the homes we have closest to campus are never vacant more than a few days. 

The closest approximation is from MLS data with the same beds and baths and in the same type of house (single, multi, apartment).

I also call it the Wild, Wild West of homebuilding since it's the closest thing to lawless homebuilding out there.

The appraiser will look at the most similar homes closest to your home that have sold recently to determine the value.  

I like them both, in general, but the best way to find a town to invest in outside of where you live if it's not affordable and if you don't want to be withing driving distance easily (recommended) is to make two lists:1. every town you have ever lived in or visited for more than a month2. every town your closest friends and family live (the ones you like)Then you take those two lists and see where they overlap with the data or lists you are using.

Ideally, if you can’t start in your town, try to choose the closest town to you with a larger population.

DSCR is the closest I've seen to something commercial

Again, they need to be closest in size, condition, location, and the most recent sales available. 

Even partnerships of the closest friends can fall apart, but putting that much trust in a stranger you've only met over the phone or maybe in person a couple times would not be a route I'd go.

I now track my final sales cost against my original estimated ARV against what the best/closest comp was when I first did my ARVs.