They're worth one cent a piece at the bank; on Ebay, they're worth more than that. A spike in copper prices will likely result in another increase in cost. It wasn't that long ago when they were going for 2-3 times face value with the buyer paying for shipping. I'm piling them up for the next time that happens. If it doesn't...well, they're still money and I can still spend them. I'm only out the loss of potential interest on the investment, although since I'm getting them for face value and I suspect that the value of the copper in a cent will always be more than that of the cent itself, I'm probably not going to lose anything even in a worst case scenario.
Should you keep them? That's up to you. They don't have a best by date on them. Deciding to keep them doesn't have to be a long term commitment. You can back out at any time without loss. I'd say to hold them until it makes sense to get rid of them - which may be right now, if you're asking about whether to keep them or not.
