Avr vs pre pro , is it really worth it??

I am stuck , and primarily because money doesn't grow on trees . Is the sound quality gonna be a substantial upgrade stepping up into a pre pro vs using my marantz avr for music listening . I know a lot of guys suggest intergrated , but I need a all in one type of system . Are the preouts on receivers partially the 7008 marantz junk , or is pre pro the real deal ?