In total, including money lost from rent, legal fees, and repairs, the situation cost almost $30k.

You have no way of knowing.Henry brings up an excellent point about going into a nursing home where she'll be paying some/all of those fees with Medicare. 

Would you be able to share what the general property management fees are on a AirBNB?

Would the investor have to use an assignment contract between him and new end buyer to collect the mark-up fee aka assignment fee at closing?

I know broker fees are $500 so $12,500 in commission?

It looks like water is not being paid and I can only see a small fee every month (that is over due) meaning the meter is likely disconnected.

I mainly want to ask if these assumptions are reasonable and if there's anything I haven't considered:(1) multifamily units in NJ close to New York City, ~$1,000,000, 20% down payment, (2) Using the following assumptions: 4% appreciation rate, 6.5% interest rate and 5.0% refinance after 5 years, $10,000 yearly maintenance fee(3) ~$6,000 monthly rental and assume 3% increase yearly with 5% vacancy rate(4) Based on the above, the calculated IRR if selling at the 10th year is ~19% (considering tax benefits) and ~17% (without tax benefits).

If you're located in WI, check out Premier Point Realty and Homestead Realty....both offer the licensing course at a discount and some of the lowest fees/commission splits in our local market.

Then you get 100% minus cleaning fees and maintenance. 

In this case, you can use Rental Income from the units that you will not be living in and that income can count to help you qualify.FHA rates are going to be lower than conventional for you almost always, but FHA does have a 1.75% funding fee.