Going into retirement soon, I am considering rental income as supplement to limited social security benefits.

I would like to work another 15-20 years and if I can get 10 properties now getting me 1,000 a month then by the time I retire I will be mortgage free and have that cash flow to supplement my income.

Some even supplement the properties monthly to carry the expenses.

First if you think market rent is 1200 charge them 1200, why would you choose to supplement their rent out of your own pocket to the tune of $100/month.Second do not provide them a term lease.

Suggestion: don't take one person's view as the sole truth and stop there, instead supplement what you read by also chatting with experienced lawyers/lenders/investors and looking at the actual legislature.2- research High Cost Mortgages and High Price Mortgages.3 - sign up for news alerts from HousingWire and InsideARM.

The only way to combat this is with a much lower purchase price, where your high cap rate and low basis can overpower the financing disadvantage, or with some type of supplemental financing.  

You can supplement with more REI using available funds and when you finish your commission, you can complete the portfolio and reach your Time freedom Point.I'll be happy to discuss this in more detail with you.

Most banks will lend 75% of the purchase and if you get supplemental financing, like a seller carry back, they will reduce the amount they lend to you.

I am a 58 year old retired teacher looking to invest in rentals to supplement my income and pay off current mortgage. 

@David Antunes 4 unit properties are residential...valuation is comparable sales method...in very rare instances you'll see income approach...but only as supplement.