It's value is well above $15k. There were 80 made, not 50 though. Last I know that changed hands went for $17000 or $17250 maybe 3 or 4 months ago?
Take a LOT of pics, post it for sale in the marketplace, pay the few bucks to make it featured (and help out Pinside), and maybe list it for $18k or best offer. I'd also NOT make it open to a forum topic because you will get endless insults and negative posts. Let the buyers contact you directly.
GLWTS.