I just multiplied that by 21 times, otherwise no difference.

Multiply the P&I payment by the number of months delinquent.

MFH seem to help multiply units quickly.

Leveraging will multiply your returns, but you might not want additional debt.

If you don't have financials, you can calculate the expected NOI by multiplying the number of occupied spaces currently paying rent by the monthly lot rent, then multiply by 12 months, subtract the expenses, which can range from 30-50% depending on variables, so use 40% for your back of the napkin analysis.

Should I multiply price per sqt ft x 2?

I like gross rent multiplier.  

Take these costs and multiply by two, and deduct that from your purchase price to compensate you for your efforts.Feel free to reach out to me directly, I have bought several buildings over the past 20 years.

Take your gross income divide it by twelve and multiply it by 0.4.

My guess is you would multiply your GP % times the proceeds from the acquisition fee, and the GP share of the profits.