Before we leave Taris, there are three shop keepers I noticed in this first part of the game. All of these shopkeepers live in the Upper City of Taris.
Zelka Forn: a Human male doctor, who was the founder of Taris' medical facility.
Easier said than done, Zelka could cure almost any disease or ailment. This was his utility.
Little after the escape pods crashed to the planet, Zelka brought the injured to his shop.
Known to Zelka was the cure for the Rakghoul disease. How would he get the serum? The serum was worth more than a mop.
Aaron Klann, a survivor of the crashed escape pods, decided to help Zelka find the cure.
Fortunately, Klann returned with the serum at hand, aiding Zelka greatly. The serum was then duplicated and mirrored.
Over a short period of time, Zelka synthesized the serum. The cure was then ready to be sold cheap to those who were infected.
Right after this was done, Zelka gave Aaron a discount on all of his stock, since Aaron refused his offer of credits. The discount was more worth to Aaron, than credits spent.
Not long after Aaron and his friends left Taris, Zelka and the citizens of the planet were slain; their fates sealed and swept.