My question again stems around using seller financing to allow them to receive a consistent monthly pay of X amount and delay/lower their tax bill in the short term instead of going through a lender to borrow 800k+ causing my mortgage to be significant part of our income roughly 40-50% of take home -  which we are approved for LOL.

Invest in as long as it takes you to write a check, do a wire transfer, or even an online bill pay4.

The differences between most software is subtle and may be how they bill for their service, support their product, or the process to use those features.

@Dave Foster   @bill ExeterMy view is without violating any irs rules your best option may be to live in the property 2 years and use the exemption.  

No matter the number of units, there is one roof, one property tax bill, one sewer line, one gardener bill, etc. 3.

The 1st job Id expect 2 guys to finish it in one day, so 16-18 man hours...so I wouldnt say their time billing is drastically high, but a a moderate amount.

High ceiling looks great but increases your utility bill.

Worth it still as now I don't have gas bills to contend with for heat which I would say was around $1k a year.

You can likely see where a 5% reduction in your taxes isn't going to do much to reduce your bill. 

Appliances do break and you need to be ready take care of the bill when that does come around.