While the first tuning is in the Cartel Market, there are plans to add more tunings to the game available from a variety of sources, including straight gameplay. The tuning is also not any more rare than other items within a given pack. There are also plans to add slots to more items that don’t currently have the tuning option, so if your preferred weapon lacks the option, that may not be forever. The answers may not mollify everyone, but they do at least address concerns.
Star Wars: The Old Republic, so adding a new cosmetic option to the game is going to turn some heads. The introduction of Weapon Tuning almost seemed like an afterthought, but the fact that it offered players a new cosmetic slot on a limited number of items that could only be gotten from the Cartel Market rankled some players. Community manager Eric Musco took to the forums to address some of the most pressing questions regarding the tunings.
Source: Official forums