I have had this item for a very long time, since 2009 I think. I have not seen any of these in trades or anywhere. How much do you think it is worth?

It comes from the July 2007 Donation Present which is currently buy-able for ~25m, and will be available next July in the CS at 250 csc (~25m). The presents have been changed to allow you to pick the item you want, so there's no reason to pay more for the item than the present itself. Minions are typically some of the less desirable items from the collections, so maybe 20m, at a maximum.

Thank you so much.