For those of you hunting for a Karma Vendor offering cherries in bulk, or a trinket appropriate for your level, you are in luck. A recent Google Document was released on reddit by user Vaporial, organizing all the items sold by the karma vendors in every zone in the game from level 1 through 70. This is a phenomenal tool for those of us hunting for a certain ingredient or skin, or simply looking to keep records of the lands of Tyria. Our thanks go out to Vaporial for his work.
Vaporial has noted there are a few issues with the chart. These, and the complete Reddit thread, can be found here.