Animate CC and After Effects CC-Do I need both?

Hey guys, so this is something that I've been wondering for a while and I'm hoping someone can shed some light on this topic. I have Flash CS6 at home and I'm currently working on an animation with it. From the past, adding audio to the animation inside of Flash CS6 and then exporting as a SWF movie file causes the audio to go all funky and grainy. I find the same problem happens with the Quicktime movie too. So I got to thinking about After Effects and how you can export PNGS from programs like Flash and composite them together with audio in After Effects. So I guess my question to everyone is: To make high-quality animations, do I need to have both Flash CS6 (or break down and get Animate CC because my Flash shuts down all the time) AND After Effects or is there another program like After Effects that doesn't cost an arm and a leg that I can use instead?

Any info is greatly appreciated!

-Megan