Firstly, this is not a complaint thread at all. Congrats to all who got the unit, sincerely!!! And thank you to Gree for listening to the players through your poll and offering the most desired prize!
If they ever offer this unit again, I truly hope they do, they should make it an individual event. My faction made a valiant effort but we came up short. We did the math and knew we couldn't make it. We even had a couple other factions coming in and out to help but it was inevitable. Therefore I spent 0 gold.
If this was an individual event I would've spent 2 or 3 vaults to get this prize so there's $300 missed by Gree.
Working with the faction is one of the most fun aspects of this game, but I'd rather rely only on myself to get the really important units.