Mega-potion of Strength is also an lv 45 alchemist leve turn-in, by the way. Because the shark oil being in short supply wasn't enough of a problem, apparently :P

With NQ mega-potions, it works out to 14250 gil / 117261 XP (before you hit 50 and leve XP gets capped). NQ PPPs will be equally cost-to-XP effective at ≤8397 gil per 3, or ≤16795 per 3 HQ PPPs.