What is the age of your business LLC? 

I also wish I had started thinking about REI at your age.

You might also want to consult local property managers or rental market reports for a more accurate picture.When it comes to estimating CapEx during preliminary analysis, without visiting the property, you can use a general rule based on the property’s age and condition.

@Darrell Overly  there are certainly enough mobile homes in the area around phoenix (East Mesa/Apache juction) but your issue may be the age of the homes and any limitations the park has on renting.   

Every municipality has different zoning variance procedures.

I'm currently helping my aging parents, and I need to be spending more time taking care of them.

I think the biggest benefit of the AIA system really shakes out to be the effective & clear communication of the guidelines and procedures for construction management, which tend to be much more muddied in the residential world.

So your number of 715k may not be too far off depending on the square footage and also the age of the cabin.For anybody to suggest otherwise without knowing more information on your specific cabin isn't giving you the best advice to be honest. 

I built my first modern 7 years ago and like you agree that some (not all) moderns will age out.

We plan to rebuild, but our neighbors are aging and do not wish to go through a rebuild.