Firstly, know that all Coachella Car Camping Passes are locked, meaning car camping passes only work together with the ticket they were originally purchased with. See the last onsite camping rule:
So if you want to enjoy the convenience and fun of Coachella Car Camping you will have to buy the Car Camping Pass together with tickets (and maybe sell the tickets you already own).
I am selling two Coachella Weekend 2 (April 19-21) wristbands with a Car Camping Pass for $800. This is for both tickets and the much sought after Car Campig Pass together, so a super fair price.
I include all of the packaging that comes with it (sticker, pins, art work, booklet, etc. see photo). The wrist bands have not yet been registered.
I'm in the LA area and can meet you in person around LA.