You guys know boulder gray has been available on the Z for well over a year now lol.
https://www.nissanzclub.com/forum/threads/boulder-gray-nissan-z-color-pics-club.594/
I'm just ball parking it and not including super rare colors or low mileage collectibles, but here is what I'm seeing:
NA
RHD: $30k-$40k
LHD: $40k-$50k
Tubro
RHD: $55k+
LHD: $65k+