Amazon offers you a chance to pay $1000 to be part of their pilot launch of their Smart contact lenses which integrate your eyes and smartphone via Bluetooth. Amazon is concerned with competitors getting their hands on their proprietary information so they put a clause in the contract that you may not resell the contact lenses and must use them until they’ve fully deteriorated. Is your opportunity cost for joining the program higher now that you can’t resell it? (Hint: imagine if the resell value was higher than the initial buy-in)