Verizon Wireless Broadband and Xbox Live…

I saw a question regarding on how to go about connecting your Xbox to your laptop that uses Verizon Wireless Broadband internet, but my question is more regarding the “cap” or “limit” that Verizon gives you for the internet. I have the 5gig a month plan, they no longer offer the unlimited, and they charge for every megabyte over that. I haven’t gotten close to going over by just surfing the web, and watching videos on Youtube, Myspace, etc. But a little worried Xbox Live would use it up quickly. Any suggestions or comments would be greatly appreciated!