This is what I do..I take the gross rent, factor in the vacancy, then take 1/2 of that number as my NOI....then I look for a 10% cap rate and DSCR of 2 to 1....

Rental gross income is $4,000 and NOI is $2,337. 

Looks like your gross rents with both units rented would be well under 1% of value, so I'd be hesitant.

Secondly, 1k after the mortgage is a good place to be, however you should analyze your gross income for the property and remove 50% for your expenses as an estimate, and I would hope part of that is at least 8% of gross rent to pay your parents for managing the property.

Reading the guidelines, it seems like it's structured exactly like FHA loans in that there are low down payments (3%-5%), and you can use a portion of expected gross rents towards qualifying income.   

As a quick rule of thumb expenses should be 35% of gross income.Go to IREM.org search for ARM certified property managers.

After creating a spreadsheet in Excel I was able to see what my Gross Profit and Net Profit would be on potential deals with the capital I have.

Here are basics: List price (assumed purchase price): $114,900 with 20%down on conventional loan at 5% and minimum monthly payments of $493.45.Gross max rent (estimated): $1000/mo or $12000/yr with 5% vacancy rate. 

We all have to learn to how crawl and walk before we can run.Let's go through the scenario. 1) say the gross rent is $5,250/month (6 condos x $550/mo) + (2 homes x $975/mo).2) you sign a master lease and give the seller $3k/month in rent/lease so you're left with $2,250.

I usually see the numbers for small multi-families to be optimistic at best on the MLS.The total potential gross should be $18,120 ($735 + $775 x 12/mo)50% rule (maybe a little high IMHO) would cost you $9,060 before financingThat leaves you with a rough $9,060 NOICap = 5.17I am very familiar with Mayfair, and depending on the location this could be quite overpriced.