Last, and certainly not least, if you focus on qualitative factors (on top of ROI), there is an opportunity to create value and brand recognition by word of mouth (marketing, and your current tenants telling their friends that you provide a quality product/service). 

Lots of Airbnb's in the area, but this gives it a unique factor?????

Heat will definitely be a factor for the second layer of shingles.

It depends on many factors that are specific to your situation.

There is a factor called Cap Rate that is market dependent and it plays an important role as it can change the value greatly.

One factor that remains at that price point is not a lot of margin to set aside money for upkeep.

You are shortchanging the REI returns because you are not factoring the two greatest powers of REI:a - the compounding effectb - the fact you can quickly get all of your cash back, and still be getting a return (compounded) from the original REI

Sometimes more, sometimes less with a lot of factors going into this determination (credit score, income, address of property etc.).

So be sure to check out all the fees being charged and factor that in.

Also a big factor is where you chose to invest.I’m happy to chat more specifics directly.