I can understand your frustration. The only thing I can do is explain what happened. The code that was supposed to have been checking for content limits (specifically when posting in forums) wasn't functioning. It has been this way for quite some time. We had to fix it up, unfortunately. A few of your sites were so busy it had long ago passed up the limits, causing this issue here;/
As for the cost of the site, we have widget that you may or may not know about called the “PayPal Donate Button” If you were to add this widget to your site, you could have your members donate directly to your PayPal account, helping offset the cost.
Click here for FAQ on how to add widgets
I hope that helps, or at the least explains why the content limits appeared suddenly.