If Amazon sells out, it's worth noting that the Lego Store restocked Optimus Prime, too, but you'll have to pay the full $180 MSRP. Lego officially denotes Optimus Prime as "hard to find." ...

It’s an Autobot, from the planet Cybertron, reporting to noble interstellar warrior Optimus Prime, who’s about to face Earth’s latest nonpolitical calamity: the planet-sucking Unicron.