You could probably just load up on tsurara, go NIN/WHM (for haste), go to Abyssea, get regen atma, find an XP party, claim a mob DC+, and Hyoton Ichi, Ni, San with haste gear and spell on. Don't bother engaging. It will be boring, but I bet it would be the cheapest route. The most time efficient route is probably to do the same but load up on all the elemental tools, or use universal, and just spam the Ni wheel. The most effort efficient route would be to just do what Sandmasterr said, which would be skill it up while you do your normal Abyssea stuff.
____________________________Jacs of Leviathan
SAM, MNK, THF, NIN, SCH, DRK, BLU 90
Woodworking 100+3, Synergy 57