All-in, I am about $600 negative monthly cash-flow, and the principal balance paydown portion of the mortgage is about $750 per month. 

Maybe some mid-sized burbs in NC or VA?

Depending on the size of the loan this might be a good fit for LifeCo money.What market is this in?

In terms of getting into apartment complexes and large transactions - it's much easier than you think.Real estate is filled with opportunities to deploy capital, but in the same time is filled with fast-talking snake oil men that will happily take your money towards a "fund" so you own a portion of a large portfolio... only to find out the fund's performance is below par, your money is locked out, and the only person making money is the fund manager from the management fee they've locked you into. 

What portion of the deal did those managing funds get wrong? 

While it may not provide immediate high cash flow, it could serve as a valuable learning experience and a foundation for future investments.Remember, successful real estate investing isn't about following a one-size-fits-all approach.

Do we just have escrow write us a check for the 25% of the proceeds after the sale, since that was our primary home portion? 

Depending on the more info, one issue is the loan size - $55,000 is going to be below many (almost all) lenders minimums right now for mortgage loans on investment properties

I'm sure if varies, but I just want a range to help decide what to do.Land is in Pilsen.You are correct the price can definitely range quite a bit depending on the size, finishes, rough materials, location, etc. 

You need to check for setbacks, frontage, lot size, elevations, and flood zones.