Always beware of the "Snake Oil" salesmen. There are quite a few FREE software that has proven good to some of us (NIK collection).
But as with all photo processing software, if you don't know what you're after, you could run in circles for eternity. To each job there is a tool and sometimes it takes time to lear how to use the tools to their max.
You could download and install Nik collection to work with Aperture so whenever you want you just go to Nik and the result will come back in Aperture. And it's free.