Help me with my internet plan.

Well, we have a wireless router and a we see our megabytes is just piling up. someone downloaded 9000 megabytes. Now we have it encrypted.

So, does runescape take up a lot of megabytes?

I know xbox live and youtube does.

Anyone have a suggestion for this problem? I told my dad to get clearwire, but he doesn't wanna have to get into the 2 year contract.