A good agreement will contemplate anything and everything that can go wrong and have a solution for it.

Notwithstanding state or local custom ALL COSTS, TRANSACTION MANAGEMENT, TRANSFER, DOCUMENTATION AND OTHER FEES, EXPENSES, TAXES, CHARGES, ASSESSMENTS, DUES, AND ALL OTHER FINANCIAL PAYMENT TO BE MADE IN CONNECTION WITH THE PURCHASE AND SALE OF THE PROPERTY AS CONTEMPLATED BY THIS AGREEMENT, WHETHER PAST DUE, CURRENTLY DUE OR DELINQUENT, INCLUDING ANY INTEREST OR PENALTIES THAT MAY ACCRUE WITH RESPECT TO THE FOREGOING, SHALL, IN ADDITION TO THE TOTAL PURCHASE PRICE BE BORNE AND PAID BY THE BUYER, AND BUYER AGREES TO DEPOSIT ALL SUCH AMOUNTS WITH CLOSING AGENT SUFFICIENTLY IN ADVANCE OF CLOSING TO ALLOW CLOSING AGENT TO MAKE SUCH PAYMENTS ON BUYER’S BEHALF FROM FUNDS DEPOSITED BY BUYER; these items shall include, but are not limited to, transaction management fees, all current, past due and delinquent property taxes, costs of credit reports, appraisals, loan fees, loan points, other leverage costs, title insurance, title insurance charges, Closing fees, tax service fees, recordation fees for the deed, and any mortgage or deed of trust, any documentary transfer tax, real property transfer taxes or deed tax that may be imposed by the State, County and/or City in which the Property is located, common interest community/unit owner’s/condominium/homeowner's association maintenance or membership fees and/or assessments, if any, Closing costs, and all other costs and expenses, including any cost, expense or tax imposed by any state or local entity not otherwise addressed herein.

I'm contemplating putting an offer in on a SFH that is split into a front/back duplex.

That seems like a good strategy, one I have been contemplating.

I've contemplated it for the past 10 years.

Is when I received "No" as the answer, that is when I contemplate on buying this system.  

That certain Letter of Approval For the short Sale of Real Property, dated xx, Xuly, 20xx shall be conditioned upon the satisfactory execution of this "Agreement" prior to settlement of the contemplated sale transaction.....

Still, with two older ac units in 2 other units, I sit here and contemplate. 

Though after some contemplation I thought maybe I should be phrasing the letter in a different way.

You also cannot own any other residential real estate at the time of the purchase.To buy with low down and no income restrictions I'd recommend 5% down conventional with monthly or single premium MI (no monthly MI) or use 3.5% FHA then contemplate/plan for a conventional refinance out if value increases post rehab/repairs as you may be able to get a lower rate through removing monthly MI from FHA or just reducing rate because the loan to value (LTV) is now lower due to the ratio of your loan amount relative to your new higher value.