There's a new option to get instant access to the AirMech beta on Steam, which is to buy the $10 Steam Starter Pack:
Similar to the previous Starter Pack, this includes Gold VIP
, 10 days of both Kudos and XP Boosts, and 7500 Diamonds. And instant Steam access of course.
And yes, this is technically a different Pack, so if Steam lets you buy it then you can get this in addition to the existing Starter Pack if you really want. Or buy it for a friend! :D