There are two locations for you to purchase Cherries in Bulk which cost 77 Karma per 25. These two locations are Dredgehaunt Cliffs and Harathi Hinterlands. Now before I get started with telling you the two locations keep in mind in order to purchase any goods from a Karma vendor you must first complete the quest they have for you. That is of course if they have a quest available if not you'll be able to buy whatever they're selling right away.
We're going to start with the location in Harathi Hinterlands. Lieutenant Summers is who we're looking for in Harathi Highlands and can be found to the southern end of the zone in the Nightguard Beach. To reach this location you will need to swim underwater and into the cave which is where the town is located. Click to enlarge the picture below if you're having trouble viewing it
The second location to buy Cherries in Bulk is at Disa in Dredgehaunt Cliffs. Disa sells a few different Karma Chef reagents so it may be wise to stock up when you come here if you're a chef. Disa is located at Snowslide Ravine in Northern Dredgehaunt Cliffs. A picture of where she is on the map can be found below.