I am sure I have gone over 250gb a few times.  But I am not sure what my normal usage per month is.  I have a router behind the gateway with the 2nd router in the dmz of the gateway.  I run tomato firmware on my router and as of the 12th of march I am now monitoring my traphic both inbound and outbound.  This router behind the gateway handles all internet traphic except IPTV of course.  So I will know if AT&T tries to pull a fast one with usage.

More to the point though we were considering pulling the plug on TV service, but I am sure we can't do that now.