Even with 60+ perms, I don't think you'll get $500 for it.
You COULD, but you'd need quite a few (if not all) rare nx guns perm, 2-3 epics.
Or MOST of the best NX guns + Perm specs\Mercs
I havent seen the pictures but I cant tell. I just know CA trading isnt like crossfire, where a single crate gun (Rare ones) like the M4 Spring go for upwards of $200.