You're right: we didn't have a Sakellarios until a few weeks ago. Basically, I'm Exilian's financial officer: I keep track of money coming in and going out, and one of my top priority tasks at the moment is to open a bank account so that we can accept donations and make payments as an organisation.
There's much more about this in the Hidden Plaza: discussion, a big constitutional change, applications for the new post and a ratification vote.