Traffic statistic collector

I'm working on a proposal to run some OCx circuits southbound to connect to the NAPs and IX's of the world. I need to calculate how much traffic I'm sending to each member and to each members' customers. I'm using cflowd to gather info from the routers but I'm wondering if anyone knows of a script/proggy/hack that can take an AS or a series of netblocks, run them against the multiple cflowd data files, parse it out and spit out a MB/sec figure of some sort.