well , it's not as easy as it sounds but the work gains.if doing it right and everyday you could even get death weps and or BD set!
to make the 15m first you need to get bags alot of them! to be exact: 36 lv 1 | 48 lv 2 | 8 lv 3
after this you could go read the from "lvl 8 to 55" guide or you could get even more bags to start lvling 8 to 65
bags needed:
36 bags lvl 1
48 bags lvl 2
75 bags lvl 3 (not sure about it)