8-15 - cyclops - I prefer Venore cause it's just nearby depot/ 2 mapclicks). But many ppl will tell You go to Cyclopolis/Fenrock(or 13 i dont remeber when u will get exori frigo)
Exori Frigo - 30 - stonerefiners - thats the fastest way to get lvl for gfb/ava
30-50 I personaly prefer meriana Gargoyle cave but other options that other players may sugest:
Spike Kazordoon - many more ppl then in meriana gargoyle cave
Tortoise Island after Meriana - need to do acces quest but You can make profit.
Btw. From 45lvl (and good skills + prays - especially for damage) You can start hunting oramond minos and issavi ;) i'm mostly doing it with 2x lvl 3 mana imbuing