Can I reserve an item that is currently unavailable?

No. We only take reservations for available items.
This is because we usually don't have reliable information on when or if an unavailable item will again be available, and if so, what the price will be.
We therefore recommend that you use our notification mechanism, which will notify you of any changes in the availability status of that item. To do this, go to the item page and enter your email address in the field provided. You can also link this to your reservations for other items.
For example, let's say that you are interested in items A, B, and C. A and B are available, but C is unavailable. You can reserve A and B, and request to be notified when C is available.
When C becomes available, you will receive a notification, and will then be able to finalize the order for all three items. This guarantees that until C is available, no one will be able to buy A or B.