You should consult with an agent or lawyer by the fact you are actually selling an option on your property $500 is way too little for the privilege and you need to get the buyers financial statements to even see if he is a possible buyer .On the surface it sounds like he is shopping your property around . 

Since there is only one existing loan and the assumption privilege is at the discretion of the Mortgagee, there is no competing product for assuming loans.  

An individual series is statutorily empowered to file and defend lawsuits; enter into contracts; buy, sell and hold title to property; grant liens and security interests; and "exercise any power or privilege as necessary or appropriate to the conduct, promotion, or attainment of the business, purposes, or activities of the series.

what a privilege though. 

Just check with your attorney to review contract(s)- Buyer gets a free "test drive" on the property, so they know the quirks of the house- Buyer can also use this as leverage and negotiating power over the course of the option- Buyer gets the privilege of the seller not being allowed to market the property (for sale or rent) by entering into an option agreement.  

Thank you for welcoming me into the community, I realized not long ago that the VA loan privilege is definitely an advantage that I want to leverage in my upcoming deals.

Each one having a different trustee who is a lawyer for attorney client privilege. 

SELLER DOES HEREBY SELL AND CONVEY UNTO BUYER AND BUYER DOESHEREBY PURCHASE FROM SELLER, THE REAL PROPERTY KNOWN AS ___________________________________.INCLUDING ALL IMPROVEMENTS, APPURTENANCES, RIGHTS, PRIVILEGES, EASEMENTS, AND OTHER PROPERTY INTERESTS EXISTING THEREON AND BENEFITING, BELONGING OR PERTAINING IN FEE SIMPLE___ LEASEHOLDESTATE_______CONDOMINIUM _______.

Appraisal came back at $359k, so the new, negotiated & signed agreement is for $359k with a $5k Seller assist.The mortgage processor just emailed me an "Escape Clause" to sign stating the following:"It is expressly agreed that, notwithstanding any other provisions of this contract, the purchaser shall not incur any penalty by forfeiture of earnest money or otherwise or be obligated to complete the purchase of the property described herein, if the contract purchase price or cost exceeds the reasonable value of the property established by the Department of Veterans Affairs.The purchaser shall, however, have the privilege and option of proceeding with the consummation of this contract without regard to the amount of the reasonable value established by the Department of Verterans Affairs."

(Of course the eviction attorney cannot refer their clients to you - as that will be a violation of attorney-client privilege but the reverse - the eviction attorney passing out your business cards to their clients is totally allowed and legal).Of course, don't expect for this to work with a single phone call.