Witb your expectations... not in a while. Lowest level boss with drops that are worth something are the Root Abyss bosses which you wont be able to solo (though definatly party-able). You can try to solo Zak if you're gutsy, but he doesn't commonly drop anything worthwhile.
Hilla drops Dabr, Wabr, and Almighty Ring recipes. I've gotten 4 almighty, 1 dabr and 1 wabr from her total.
Root abyss bosses can make you filthy rich if you get a lil bit lucky.
Helisium mini bosses drop equips worth 300m-1b if lucky