There's often a financial component to any aspect of consensual BDSM play (just browse through the sex ads in your local alt weekly), but in the world of moneymistresses, pay pigs, and human ATMs, the exchange of cold hard cash for the privilege of being abused, dominated, humiliated, and/or ignored is the whole point of the action. Kudos to all the canny dommes out there who take the concept of sex and capitalism to a whole new level. (Funny, but we've been in a masochistic relationship with the custodian of our student loan for years and never realized the possibility of actually enjoying the situation.)
Alexandria: Your Money Mistress (Alexandria's monthly expense catalogue @ financialmistress.com)
Pay-Pig.com: Mistre$$ Linda (pay-pig.com; see also Mistress Linda's human ATM galleries @ Rich Girl's Fool)
Goddess Kalyah - Spoil Your Moneymistress (goddess-kalyah.com)
MoneyMistress Diana Vaughan (moneymistress.de)
Money Slaves (directory, discussion forum, and gallery @ money-slaves.com)