Some charge based on account value, others per transaction, and some use a combination of both.

I'm California-based where there aren't any real deals in my area, so I'm exploring Detroit as an alternative real estate investment market - due to the combination of it being a strong market and my having connections in the area. 

I'd underwrite the deal as any other - make sure you are conformable with the quality & tenant base. 

This will vary based on region but in general 2 – 5 points, 9% - 16% APR (meaning this is the annual rate so divide it by 12 to get the monthly interest amount), and documents fees can be from $600 – $1,900.

@Joseph SpearGood feedback, but would be careful about buying based upon Cap Rate with Homeroom as you outline.Just have to look back at Airbnb history. 

However, these programs typically qualifies borrowers based on their income, such as tax returns.The DSCR would be a good option considering you and your husband are entrepreneurs and the tax returns don't look good on paper.

I know of several DSCR and portfolio lenders who offer different terms based upon your situation.

In the past 10 years, Ocala has greatly improved the employment base, adding tons of logistics and distribution jobs on top of the medical, service and equestrian jobs that we have always had. 

Another good thing about that is that you can do a cost segregation study based on the percentage of the house that is being rented to your house mates.

I was kind of skeptical, but seems this city/town is good place for STRs based on your response.