The same fact pattern as above, except that it turns out on Tuesday, the parties wrote the following on a piece of paper and they BOTH SIGNED IT$.$ The paper says, John hereby agrees to sell his Fender guitar to Paul at a fair price to be agreed upon between the parties on Thursday.

$[$For reference only, question $1$ said: "John and Paul are both adults. It is Tuesday. John agrees to sell his Fender guitar to Paul and Paul agrees to buy the guitar from John on Thursday. They agree to finalize a 'fair price' on Thursday. On Thursday, the parties negotiate the price but cannot come to an agreement. Paul still really wants the guitar. Can he successfully sue John for it$?"]$