Adding to what gener7 said, think about the pros and cons of each option. You can get a perpetual license with CS6, but any new features (like updated RAW support and creative options like the Path Blur filter) will be non-existent.
The CC sub will grow with features and updates but, of course, as you know, it's a sub. (Also take note that CC has the features of CS6 Extended plus whatever came with CC.)