F2Playnkton - Spends nothing.
Minnow - Buys little. 99¢ - $1 packs are a must and occasionally the $5 monthly.
Goldfish - Spends for guaranteed banners only. Also buys the $5 - $10 monthly.
Swordfish - Spends a little more than a goldfish, but not enough to be a dolphin. Around $10 - $50 in a month.
Dolphin - Spends semi-regularly. $50 or $100 packs as needed.
Whale - Spends regularly, will comfortably drop well over $500 once a month.
Leviathan - Spends freely without constraint, $1000 - $5000 a month, and maybe more.
Cthulhu - Basically funds the entire goddamn game.