It's not about the dollar value, it's about having a contract. In a contract, the parties usually agree to do something in return for something else. This NDA i

It's not about the dollar value, it's about having a contract. In a contract, the parties usually agree to do something in return for something else. This NDA is completely one-sided. The author gains nothing. So basically it is a gift, and not a contract. And in many legal systems, it is easier to take back a gift than to undo a contract.