I saw one for $1600 a couple of years ago.. second hand. I didn't dare to buy it, because I thought it must have been a scam for that price.
I guess you could order them trough an authorized dealer, but why buy a signature model, why don't buy the real thing? :
Gbase - Gear Details
Or if you do want all 3 of his signature models:
Gbase - Gear Details