The assumption doing the most work here is that your buyer's 21-day pattern reflects preference rather than requirement. Those are different constraints. A buyer who closes fast because his capital is idle and his acquisition pipeline is thin has room to wait. A buyer who closes fast because he has a 1031 deadline, a fund distribution date, or a bridge loan maturing does not. Before you model any structure, you need to know which one you are dealing with.
If the timeline is flexible, the option agreement is the more defensible structure for your side of this. A purchase contract with a 60-to-90-day close does hand the seller ongoing optionality, and in a probate situation where the executor is fielding other interest, that matters. An option locks the property, removes it from consideration, and gives you a defined window to deliver your buyer. The cost is the option premium, which becomes a negotiation with the estate. Confirm with a probate attorney whether the executor has authority to grant an option at this stage of the proceeding, because that authority varies by jurisdiction and by how far along the court process is.
The risk you did not raise is buyer drift. A 60-to-90-day hold is long enough for your buyer's criteria to shift, for a competing property to land in front of him, or for his capital to get deployed elsewhere. Fit on every line of the criteria sheet today is not a guarantee of the same appetite in week eight. A soft verbal commitment from the buyer before you negotiate the option is not enough protection. You want something in writing that ties him to this property, even informally, before you spend money or time on the option.
The regulatory angle is worth noting too. Depending on your state, how you structure the option and how you communicate the assignment to your buyer affects whether this stays in the private-transaction lane the strategy guide describes. Run that past a real estate attorney in your jurisdiction before you execute anything.
What does your buyer's actual liquidity look like right now, and does he have any capital deployment obligation that makes a two-month wait structurally impossible for him?
