Given the time constraint of 3 days and the need to complete the refinishing job, the best option for Jorge is:
He should buy the sander in the store and pay more.
This option allows him to get the sander immediately, ensuring he has enough time to complete the refinishing job within the deadline. Ordering online could lead to delays, and trying to fix the old sander may also take too long. Turning down the job is not a viable solution if he wants to complete the work.