The current rental cash flows ~$400/mo.

Basically saying the seller would pay a commission of XX percent based on the agreed total amount of an executed purchase and sale agreement.This way the seller does not play games with commissions.

Are you cash flowing the property?

If you could increase the rental income for the landlord and split the increase in cash flow it may be possible.  

If your sale is something large enough to split then a transitional strategy of buying a modest NNN for cash and then leveraging on a single family home, or a DST to absorb your debt might be just the fit for you.

Mason welcome to biggerpockets I also went to UW-WSuggestion for the next 10 years , if possible purchase four plex , duplex , triplex, last resort sfr for house hacking ( no immediate cash flow )Rinse and repeat until your personal lives change ( family, relationship, etc )Each state you purchase property :Develop a decent team to handle your investment properties while you enjoy your fishing/etc

Here you will meet wholesalers who provide deals and all the cash buyers (rehabbers) you will need.To find out about an area go to IREM.org search for ARM certified property managers.

Purchase price: $125,000 Cash invested: $20,000 I love duplex's.

And that's not even touching on getting you into positive cash flow territory and the passive income you mentioned that you'd be looking for. 

Which is the best, relatively safe Philly neighborhood for finding a potentially cash-flowing small MF (3 to 4 units)?