Cost of traffic data access?

[Peter Fairbrother]

If the Police want to get traffic to and from a server/IP address, how 
much does it cost them? I know the ISPs charge, but can anyone say how much?


For a more specific example, suppose they want a month's traffic data to 
and from a TOR node - quite a lot of data, size, time, IP addresses - 
but only one IP to watch. How much?


Thanks,

-- Peter Fairbrother