Which (used) Grado Headphone?

Looking to spend $700 max (used), preferably less.  That would seem to eliminate the PS1000e.  I'm looking at RS2e, PS500e, GS1000e (and probably a few others I can't remember).  To be used with a Chord Mojo. I listen mostly to Jazz and electronic music.  I have a few Hi-rez files but mostly I will be listening to Tidal or Pandora.  thanks.