That isn't so easy in virtual life. I'm seeing a disturbing trend of greedy douchecanoes setting themelves up as Financial Dominants just so they can finance their virtual life at someone else's expense.
In a concrete-life Financial D/s situation, a responsible Dominant will execute a contract, signed by both themselves and the sub/slave, so that the sub cannot come back later and try to claim the Dominant robbed them - and also to protect the sub from unhealthy exploitation.
In Second Life, I know this isn't happening. You're getting greedy ass sons of bitches claiming to be Financial Dominants who wouldn't know the first thing about being a Dominant in the first place. What's worse is you're getting inexperienced people who are buying into this scam, and forking over money to these charlatans.
I found out this morning that a Bloodlines clan was founded, just for Financial Dominants and their slaves.
Take it from a Switch who was trained by a concrete-life Master, who not only knew what he was doing, but had ethics to boot - DON'T FALL FOR THIS. In nine out of ten cases it's a complete scam and the so-called Dominant doesn't know what the hell they're doing. They just don't want to pay for their own Second Life.
If you are serious about doing this virtually - and I don't recommend it, as so many can scam - get to know your Dominant to the point where you know who they are in the concrete universe. Discuss signing a RL contract with the Dominant, and make it one that can be terminated at any time, without any sort of backlash.
Protect yourself. Your submission, in ANY form, is a priceless gift. Don't just be giving it to the next Tom, Dick, or Mary who claims to be a Dominant.