Make sure they know you are offering to pay down the principle.

Right now economy is good, stock market is high, unemployment low so the possibility your family/friend tenant will have Employment issues are low. 

I took a few real estate and stock trading classes when I first got started.

Most of the 50K will go towards the interest and smaller portion towards principle.

It is very similar to buying stock in a company; thus, you don't get the same tax advantages as buying real estate.

This is a really old post but bigger pockets calculator does it this way:Monthly Income / 2 - Principle & Interest = 50% ruleThe image included is directly from the calculator.It does not use NOI

The wood is very thick, probably 50% thicker than stock cabinets.  

While I agree with @J Scott in principle, not everyone has the retired father-in-law or uncle that is looking to do better than an US Treasury Bond in retirement, and thus, can't always do business with people they know.

They are getting less than 2% return in the stock market and it is driving us crazy.Now we are looking at:  Cash out?

@Steven Lapp - Proceed with caution and vet people and companies for for managing your real estate assets as strictly as you would if hiring a financial planner to turn over your $250K stock portfolio to.