Crazy way to multiply liability on seller financing.

And Jay you are 100% right sub 2s are very dangerous and having multiply exit strategies available is a plus and need.

So does he give up one source of revenue now, to give him the opportunity to multiply his revenue elsewhere.

Divide by 144 to determine monthly expense then multiply by 2 for the duplex.

Then the home was always used as a residence from time of purchase up until the last 2.5 years or so, which is NOT to be included as "non-qualified use", so the "Home" version should have 0 non-use days by the days owned, making my non-residence factor a big fat 0%, which multiplied by the gain makes my non-qualified use gain another big fat $0, meaning that my gain that is eligible for exlusion is 100%!!!!.......

Multiply $898.82 by 12 months then by 15 years is only $161,787.60. 

Multiply $898.82 by 12 months then by 15 years is only $161,787.60.

Multiply those probabilities by one another, and you have a huge undercurrent of risk ballooning and compounding with each passing month. 

Is there a standard multiplier like say 20% of rent goes to vacancy and opex? 

I believe the one good thing about that spreadsheet is that it can be adjusted by the State you live in. because costs are different in every State the estimate sheet i believe is based on a multiplier for the corresponding State, as most cost estimating books are based. that program does break down a lot of information for you and i think it is a good program, one thing you may want to check is if the program updates every year with current multipliers for the States ( program is probably based on a starting average value for each thing and then the multiplier changes as prices for materials change) and you want to make sure it does that.