As of this writing, the campaign had passed $4.5 million and Canonical had added new funding tiers for $625, $675, $725, $775, $780, $790, $800, $810, and $820; these tiers were added to the existing tier of $830 and the sold out $600 tier. Unfortunately, as of this writing the $625 tier had already sold out, and the tiers from $675 to $775 only have room for 1,250 contributors each.
No doubt the lowest tier available will garner the most attention until it sells out, at which point the focus will shift up to the next level. This basically means the faster you donate, the cheaper your device will be. So, if you're interested in a device that will dual-boot Ubuntu and Android, dock to become a full PC, and feature "the fastest available multi-core processor, at least 4GB of RAM and a massive 128GB of storage", and a 4.5" 1,280x720 sapphire crystal display, you should check out the funding page.
source: Ubuntu Edge Indiegogo