There are several duplexes out there for sale and if you do it right, it can be financially beneficial for you.  

But if it’s a sale, some buyers might be okay with a few unfinished details, especially if you disclose them upfront.

This defers capital gains and depreciation recapture taxes on the sale of your fourplex.After converting it into your primary residence, you may qualify for the primary residence capital gains exclusion ($250K single/$500K married), but only for appreciation after the conversion; gains from the rental period remain taxable.

If you are looking to do real estate sales as well you may want to find a brokerage that hires for both at the same time, and check their credibility.  

Would a low enough sales price make all of my concerns go away?

Jan we had 12 buys 10 sales. 

But on this specific guy, I jumped on a call to explore the program and it was a high pressure sales call, it did not feel organic, not trustworthy and certainly did not feel the right fit.Why would someone spend 10k on a so niched-down space of real estate when they can get someone for the same amount to teach him/her everything?  

I have the credit, experience and the knowledge on how to underwrite the deal to show their ROI in this arrangement vs a traditional sale. 

If it doesn't work, put it up for sale when the lease ends. 

Your new ARV(after repair value) should be supported by an adequate amount of comparable sales in the area(duplex's).