Answer:
Since both parties can breach the contract without fearing any penalty as a result of doing it, its execution will depend on the good will of both parties. It will also require a coordinated action where B hands out the money at the same time they are receiving the deed. If both things do not occur simultaneously, for example, S promises to deliver the deed the next day or B promises to pay the next day, they will not do it. For example, B pays the $5,000 and S decides to increase the price to $10,000. Or S gives the deed and B says that the agreed price was $1,000.