@jamesTo expand on what @Linda Weygant said about the home office deduction no longer being an audit flag, the IRS now allows a "simplified" method where you simply multiply the square footage of the office by $5 and that's your deduction.One has to think that if the IRS is offering and encouraging a simplified method of reporting, it's not going to be the cause of an audit.

It's a multiplier value of almost any other market out there, or in % speak that is to say 200%, 300%+ MORE available rental inventory for tenant's vs other markets.   

That should multiply your income when second unit is rented.

Think,, if you can put down 10%,15%,20%, that means you can multiply your portfolio, and cash-flow with the same amount of money.If you haven't seen @Brandon Turner's webinar about "How to Invest In Real Estate With Other People’s Money" you should.

I have also seen appraisers use a calculation based on the unit's rents and the area's average gross rent multiplier as a supplement to the comps. 

Rent multiplier, never pay more than 100x market rent, it's that simple.

I try to get about a 1.25-1.5% multiplier pruchase price to rent (i.e. $100,000 home would rent for between $1,250-$1,500.

What’s crazy though is i could probably multiply that as well. $177k of fluid, liquid capital would be a small dream come true for me and I have 0% doubt I could multiply it.

The regional county multiplier is sky high and nobody cares.5.

Lot rent only multiply NOI by 0.7 (30% expense ratio).