So, this can be seen as both positive, and negative. Before that, I need to explain what my idea is. A daily or every other day form of taxation. This can raise and lower depending on your money [There should be plugins for this] and should not affect you if you have a certain amount [Say...1000 for example is the max limit of being nontaxable].
Once you pass this 1000 limit, you are taxed daily or every other day at maybe...1% or so; until you are at/below 1000.
Now; This does two things. It makes people want to horde more money.
"Oh no! I'm going to be taxed and lose money! I need to get more!"
Players decide to get more money, and it raises the tax-rate of their player by someodd percent. This is a very VERY slow and gradual increase, as to not make gaining money impossible. Especially if it's daily or bi-daily.
This is something that obviously would need to be hammered at greatly to make it efficient and effective.
This also comes at another possibility. Players pay each other to do tasks. Say Pete is running low on funds, he decides he'd offer his services. John has extra money, and he's not exactly a hoarder when it comes to money. John could pay Pete a certain amount [To be determined by players] in order to keep their funds up.
Again, this is an idea that needs to be hammered out. I'm curious of what others may think of it. Personally, I hate the hoarding of such large funds. Nothing against players who do it; I just don't enjoy it. It also seems daunting when there's no way to ever catch up to these players, especially when you're brand spanking new.