Aeon Collection can be purchased for $399 or if you wish you can buy each library separately for $299 (Aeon Melodic) or $199 (Aeon Rhythmic). The price is pretty standard for that kind of library in terms of quality and content that you get. The dilemma comes when you have to decide whether you will buy Aeon or rather another synth and make everything yourself. In either case, Aeon is worth looking into. More here.