Without status, you can only upgrade the highest fare classes (Y and B in Economy, as stated by aa.com here). Given this I'd not personally waste my money, though the upgrade instruments will remain in your account "forever" (as long as you have an active account).

Mine have been around for years - I'm only sorry they don't earn interest or multiply . As EXP I don't earn nor do I need to spend 500 mile upgrades, but I accumulated bunches of them that are still there, other than those I spent for "sudden travelling companions" like WWII vets and the like I met at the airport.

We'll merge this into the 500 mile upgrades thread.