Don't they sell pure ghost anymore?
cause I'm trying to find one but can't

Pure ghosts and pure DQs don't exist. ~firebolty

Pure ghost would be a pain in the ass to see. Hence why it's not there. It would also be unfair to new players and what not.

ahh...so you can't actually collect full pure then? :/

Incorrect. You can collect full pure and get the achievement for it. But unlike the other items, pure only needs 14 to be complete. Meaning you don't need to buy a pure ghost or a pure dq to complete it.