You have to ask, and answer, the exact, same question that the SELLER will ask:
"Is the Selling price worth putting the money into the well?"
If the Seller says "NO!:, then they are stuck.
If you say "NO!", you can just walk away.
The well is kinda important to the House, the Sale, and the Property. Kinda!
If the Buyer was doing an FHA or VA loan, they probably would not get it approved. The Seller would still be stuck.