What the "sticker price" was and what it SOLD for may be two different things. Anyone who configured a Brabus Cabriolet could probably tell you what the "sticker price" is on one. I did a Coupe it mine came out to about $18,200. the Cabriolet was probably $20,000.
But as someone said, it's up to the BUYER to disclose what they paid for it.