. $125k  gross equity .Probable real spendable equity of $97.5k.I'd just sell. n pay the tax. 

So with the borrower’s upfront payment of $1140 and they’re catchup payments of $2600 we’re looking at a 30.5% gross ROI in 2 months!

I've had commercial properties where the PM basically took around 6% to 7% of the gross revenue.

That would put annual gross rents around $6000, assuming 50% expenses.

This will give you the potential gross revenue.

I understand that I have to identify one or more properties to swap with a total value of the sale of my property: are we talking about the gross yield  (600K) or the net yield (570 after after the real estate fee)?

you can then take the scheduled gross rent deduct the expenses or just 50% for quick check. what you would have left at 50% will be your Estimate NOI.NOI/Purchase price = Your Cap rate on cost.  

@Brian Kraft depending on age I use 50% to 55% on total cost to gross rent that is my rough in number.

Your family member could also provide the financing on it and make money every month with a positive cash flow spread between the debt and the rent collected or be like a guarantee person that is the main backer for the long term loan your Bank or other lender that  owns that property with a long term loan with that property  on a security  loan until that loan is paid off.Not saying the fix up budget makes this decision fairly difficult but i would say to not have a house that needs over $5,000 on the "make ready" expense to make a 20% gross return giving a cost price and sales price you gave on your example.What you could do to find a deal is pretty limitless. 

ask for last 3 years bank statements, signed estoppel statements, and/or a signed purchase agreement that explicitly indicates the gross and/or net income of the park is true and accurate.