I also just generally compared to the 1% rule. 

Quote from @Emory Clayton: I'm confused as to how to screen Sec 8 tenants compared to regular 'market rate' tenants.

You should think about what you would offer with regards to your competition and compare rents.

I needed to replace one, and they are very expensive compared to a standard 30” model.

I started calling other mobile home parks nearby, to get an idea of comparables.

Since they can't do each property individually, they use comparable sales to make broad generalizations to determine percent changes.

You may find that you can rent a much nicer condo compared to what you would pay on a mortgage for the same number.

Quote from @Bryant Brislin: Land in the path of development that may seem a little far out, but your gut/intution and common sense from an urban planning perspective tells you that some day, whether it's in 10 years, 20 years, etc it will be a great long-term position for your family to have and hopefully sell at a signifcant multiple return compared to what you've paid for it.

There is a chance their unit is also pretty dated compared to the others or others in the same neighborhood.

I would compare it to BDC.