Is there anyway to just purchase Photoshop without it being monthly/annual? Just buy and go down the road. Does it have to be cloud based? I'm sorry I'm old school, purchase software and not after always be tied into the internet to accomplish everything.
You can still buy CS6 (that I know of, anyway), however, depending on the version, it'll cost you about $700 USD for Standard (no 3D features) and about $900 for Extended (3D features). If you went with the Creative Cloud Photography Plan, you'd get Photoshop CC and Lightroom and any and all updates and new features associated with those apps, until Adobe falls off the face of the earth.
(I'm not trying to push anyone towards one or the other here; I just want people to be fully aware.)
Be aware that outside of critical system and camera support updates, there aren't going to be any new features added in CS6. (Its version of Camera Raw, for example, is not as fully-featured with any of the new tools like CC's Camera Raw has.) CS6's shelf life will depend on operating system support at this point (as has always been the case with the versions of Photoshop up until Creative Cloud was introduced).
Piling on to that, all the features of Extended are included in CC. (There is no Standard version of CC; it's the whole shebang.)
You don't have to be connected to the Internet all the time; CC requires check-in about once every 30 days.