my father in law gave my son a completely unused park hopper from 1996 that we had planned to use for our upcoming trip. My husband's wants to hold onto it for sentimental reasons/ value. He thinks it may increase in value but I cannot find anywhere that it even had any value past saving us $300 on a new ticket. I'm wondering if we should hold onto it or use it? I know we can use it but would there be a reason not to?