User blog comment:Tmunger/Repairing the Pharos - Third stage quests/@comment-69.119.135.174-20130130210705/@comment-3991817-20130130223053

Yeah I remember some people saying the visitor with the projector bubble does not respond properly. Try tapping the visitor himself instead of the bubble (turn on invisible view mode if necessary) and it should give you a pop-up asking if you want to buy the porjector.