There was an announcement which let people know about submitting gifts.
Also, it should be noted that the event page has [Gift Items] on it, which shows the site inventory, which means you need to trade your items and then submit them.
There will honestly be no way.
I think that Valve knew that refined metal would eventually tank in price, and refused to fix it. This refined price falling into the "nothingness" range will force people to buy keys, and thus more profit for Valve from their guinea pig game.
Next time post in the Help & Support section.
Item Factor basically makes it so you have to overpay if you're using items other that pure (i.e. keys and metal).
Say you have an item worth 16 keys. Under an Item Factor, let's say 80%, it is NOW only worth 12.8 keys for the auction bid.