Hi everyone!  I'm a newbie here buying my first condo property here in West Town Chicago, and am wondering if anyone has bought property with or has thoughts on an interest-only loan that is fixed rate for x amount of years (<30) instead of a regular fixed 30 year mortgage for the sake of maximizing the equity you get when you sell?

For context:
I intend to live in the unit for at least 2 years, then rent it out (cash flow is ~200$/month in the current market, way less than 1% cap rate), and eventually planning to sell it in 5 years where hopefully the appreciation has kicked in so that I can use it as a down payment for a duplex to start building more wealth. 

The reason I'm considering this is a regular 30-year mortgage starts off with me paying $465 for principal and $1020 for interest per month, whereas with the interest only loan with fixed 10 year rate: I will start with paying $564 of principal (with the same total monthly payment). So just as a ballpark, averaging that 100$ over 5 years is an additional $6000 into the equity, which is not a lot but not nothing either.

Of course, there is additional risk with taking this interest-only loan which is only fixed rate for 10 years, but in my mind it seems very unlikely that I won't be able to sell the house in 5 years (between 5th year of when I start trying to sell and the fixed rate of 10 years). Do you think it's worth taking that risk? Is there something I might be missing? Would really appreciate all your inputs, thank you!