Earlier quoted context omitted.
It doesn't have to work that way. Internode, an ISP in Australia (for consumer connections) will monitor your usage, send you notices on how close to the cap you are, and then shape you back to slightly faster than dial-up speeds. YOu then have the option of checking your email (slowly) and maybe chatting, or purchasing a datablock and becoming unshaped within the hour. (I semi-regularly purchase blocks during months…
Is their line running at near capacity at all times? If not it seems not only not fair, but silly to have their network lines sitting mostly idle for the last week of every month.
If the telcos are not price gouging, there shouldn't be a problem with data caps. Stop being a cheapskate!