Since the Borg is so interested in money why not do the following to keep and gain new members:
In my humble opinion, money is NOT the primary purpose of the WT. I think that exercising power over other people and having people who outside their organization are big fat nobodies, having "prominent" positions as well as the chance to influence other people's lives, is what gives them the real orgasm, not necessarily monetary gain.
Proof of that (to me, I'm keeping this in I statements) is that they do want to make money but discourage their own people from making money and prospering. They do have a stronger take on people's private lives and personal decisions than in controlling people's finances and money. They do not impose their members to give money, but they do impose themselves in every aspect of their lives.