One last challenge is their estimate of property taxes - they are all VERY low:(Michigan has some interesting property taxes because there's a Taxable Value and a State Equalized Value, as well as Homestead and nonHomestead millage rates. 

She had a choice of putting down a deposit equal to two month's rent or paying monthly "deposit insurance." 

Point being - if appreciation is close to equal to the interest paid on savings (5% currently) - wouldn't it be much easier to take the 5% from the bank with no headaches associated with owning the property?  

So to answer your other question,  the estimated cost for this build 3 times the cost of that duplex build for roughly equal square footage and including the lots and utilities and everything for both. 

This locks in your monthly expenses, versus  HELOC that is variable, and matches well to the long term hold of the rental.I use HELOCs for shorter term capital needs, i.e. flips, or even possibly the acquisition and renovation of a rental, but always with the belief that I will have it paid off in under a year, typically 6 months.  

@Peston Parsard not sure if enough viewers will note & care about free internet and pay more in rent.Regarding the MLS listing, going to guess your PMC isn't charging you a Placement Fee equal to one month of rent?

It is a long held belief in investing that you  "Marry the property and Date the rate".  

Do we just lower the sale price by equal amount and the contractor will need to take payment from the new owner? 

What I've learned in the end is that these home inspectors are not skilled in communication and they treat a small issue equally with a crack in the foundation or faulty electric panel. 

Properly executed, an investment in these types of property can garner substantial passive losses, often equal to the amount of capital invested (or more) even in years where the benefit begins to sunset.A few words of caution: - Be careful not to let the "tax tail" wag the dog.