At that time, you will use an assignment form assigning the contract to the new buyer for your fee and stipulate that they are to place $15k of EMD into escrow that is non-refundable and to be passively released from escrow to you.

One problem I can see building this stipulation into a lease  in a duplex or triplex is... how do you decide which unit has to do the work?

So many people conform and think inside the box and they dont process these kinds of stipulations untill something happens.The apartment referances are pretty much off topic for this thread, they have a place like i said before.

We document the deal with a written Assignment of their contract (for "$10 and other good and valuable consideration"), which I bring to the closing table; and a written side agreement that stipulates the financial arrangements, terms, conditions, etc., which is treated as an actionable yet confidential side agreement.Short of that, I will pay a "scout" something like $250-500 for facts surrounding a property that may be available, including the seller's contact information.

Whose address is: (ADDRESS).Closing: Closing will be no sooner than 45-days and no longer than 60-days from the date of acceptance this contract as demonstrated by buyer and seller signing this agreement. 45-day date: 60-day date:Title: An unencumbered, marketable title to said property to be conveyed by deed of General Warranty, with the usual covenants such as any title company will insure, except easements of record, restrictive covenants of record as to use and improvement of said property, and except applicable regulations imposed by any planning and zoning commission.Contract Stipulations:-Outstanding property taxes shall be pro-rated between Buyer and Seller as of closing date.

Your loan will stipulate how much equity you need to purchase a property. 

What does the contract stipulate regarding their right to extend the closing date?

Whenever I rep a tenant where this comes up, granted I traditionally work in retail spaces so your asset class might differ, we stipulate that the tenant will handle repairs and maint. of the HVAC units, and in the case of replacement the tenant will only be responsible for the prorated, pro-rata share of that expense for the term of the lease. 

@Christian Hutchinson You can add that stipulation in their lease but this is still Detroiters we're talking about...

The only stipulation is that your buyer must have their financing lined up and their wire must be received at the title company (same title company required for both closings).