I have $40k in savings and very low living expenses.

You will have to stay in one  of the units for at lease a year , but the great thing about this is you will the income from the 3 other units to hel pay down your expenses on that property

Many landlord will install separate utility meters in multis to off load this expense. 

Also you'll get more depreciation expense depreciating the appliances over their shorter useful life than including them with the house at 27.5 years.

I just ran a property that I would love to buy if I can find the private money or possibly the hard money at the right rate and ran it through the BRRRR calc.All looks great except when I look at the financial projections section I see the following...50% Rule Cash Flow Estimates Pre-Refinance Total Monthly Income: $2,850 x50% for Expenses: $1,425 Monthly Payment/Interest Payment: $600 Total Monthly Cashflow using 50% Rule: $72 50% Rule Cash Flow Estimates Post-Refinance Total Monthly Income: $2,850x50% for Expenses: $1,425 Monthly Payment/Interest Payment: $556 Total Monthly Cashflow using 50% Rule: $869Am I missing something or should the total monthly cashflow Post refi be that high?  

If you have 150k, you might want to consider a more expensive 4plex.  

Now at the same time the renter is paying all  the house expenses as well as the interest on the loan   There is no way to get these back.

Same question, can you receive higher than market rents and is your profit higher or are there additional ongoing expenses.

Then, I would use the money I am throwing away on living expenses every month to help me pay down my debt over the course of about 4-5 years.

I feel like purchasing a duplex, living in one unite, renting the other out, and purchasing a deal where the numbers work correctly to where my living expenses would be paid for by my tenant, would be an excellent way to not only help me achieve my goal of paying off my student loan debt, but also help me get a taste of what land lording is like to see if it is a route I would enjoy taking.