Thats my plan, live in one unit and rent out the other.If you could break down all the variable costs it would be appreciated, thank you    

I don't know about Greer, SC, but it can be pretty variable neighborhood to neighborhood in Chicago.

What I'm not sure I understand is the HELOC repayment process on a variable interest rate. 

For our primary mortgage, we are 2 years into a $600K 30 year 3.75% fixed conventional loan.Here are some pros and cons I can think of for each option:Invest as CashPros:Very liquidLess riskyNo interest on cash amount for next investmentKeep higher primary home interest expenses for tax write offCons:Sits in savings account earning 1% until reinvestedPay Down Primary Mortgage and Take Out HELOCPros:Saves $275,000 interest and reduces payoff during to 15 year on primary mortgageCons:Puts primary home at risk if future rental property investment goes badHigher and variable interest rate on HELOCBanks could close HELOC at any time removing my access to the funds for investmentMiss out on tax benefits of higher primary home interestUltimately, our goal is to have no personal debt including primary mortgage, while building a steady stream of cash flow through rental properties over time. 

That being said, I would be concerned about the occupancy and if the leases have a variable ending date and its age, and if you think you could add any value to it by raising the rents or make any interior or exterior improvements. 

For instance, 7/1 ARM is being offered at 3.75% for the initial 7 year period, with LIBOR based variable rate afterwards.

@Sochima Eze Especially consider no this variable is such an unknown... you may have a tenant that wears shorts all winter long and pumps yhe heat to 85!

He has a variable interest rate and it recently increased the $400 which has caused the hardship.

I am not yet sure the terms of financing at this point, but likely fixed for 5 years around 5% then variable.

If any of the variables go haywire, it could eat up your entire profit and possibly cost you money.