My duplexes are the least profitable and most time consuming.

All things considered, I’d say you could have an honest conversation with the tenant and do a modest increase to help you increase profit and get closer to market and the tenant, who I assume has been there with the unit not fully updated already, doesn’t mind staying in the less attractive unit for the more attractive price so it still helps them.

(That’s $1,500 profit and all my money back) $1,100/month rent.

We used the profits to move on quickly and buy a house in a much nicer area with a good bit of equity already. 

I have plenty of money in a Roth IRA that I continuously max out, as well as a profit sharing account through my company, so I do have some investments started.

Just make sure the money guy gets his money back first and with some profits.

But if the upside is an extra 30k in NOI, I'm not willing to pay for 80% of that, leaving myself with only 20% for me to profit on.

I feel like this should be a basic question but it's hard to find a definitive answer to.We'll be splitting the cost, labor and profit 50/50 but have no entity setup at this point.1.

I use a separate bank account for each property, so my bank statements become my profit and loss documents.

you have to be positive that the numbers will yield profit for all involved parties. if you aren't sure of the exit strategy or how you will secure funds then you still have a far way to go. do you have cash buyers with verifiable proof of funds lined up?