There are other flaws/mechanics in this game you can abuse aside from cash etc.
You can abuse the fact that ur party members can join party once u have started a dungeon solo and then your doing solo difficulty with 5 people, you can abuse the fact that when u die and run out of soul eggs in a party u can just re enter a dungeon with 1 free life. there are many ways this is possible doing it fast is something special.
this is probably the coolest achievement yet since being top level isnt much of a big deal since there are botter like speed hackers already well atleast thats what i assumed i seen today in a party of mine.
Nice job tho sorry to off track cool achievement