How much are my mavics cxp 12 worth?

I know someone that wants to buy them but I don't know how much I should ask.

what a stupid...blah blah.
advertise the fucking things at a price you want to sell them, then see if people buy them.
If not decide if you want to keep them or sell them, and then change price or withdraw them.

WTF eyebrows I've never heard you talk such bollocks.

If you read the OP it mentions their is a buyer already, followed by a polite request for help.

If your suggesting Joao+bcn adverstises, and then withdraws the ad pending a response – that's wasting everyones time and is basically dishonest.