What is the minimum interest rate we can charge for the seller financing without causing any red flag with the authorities?

In today's market, HELOC rates could be a dealbreaker on trying to do that so be sure to look through all your options first. 

Or this is just basically a fee land lords have to pay ?

You guys are doing awesome, and don't forget to track those interest rates.

I get the owner's statement every month (from Buildium) that shows rents, vacancies, property management fees, maintenance expenses, etc. 

Of course, the virtual numbers that the tool spits out have to be validated "the old fashioned way" by confirming the assumptions the tool is making (comps for daily rental, occupancy, vacancy rate, seasonality, etc.) 

@Reitta Seidel I would submit that it's always a good time to invest, you just have to figure out what the best options are in the given market.We focus on first time home buyers who are less rate sensitive and are more likely to buy in all markets. 

Most keep the late fees ect.  

at 3% interest rate, that would be amazing.

Which reduces Cap rate.4.