Running any government agency consists of many "colors" of money from appropriated funds to personnel costs to operations and maintenance. In general, 2005 data from the IRS shows the total cost to be about $10 Billion. You can access the raw data at:
But realize the IRS will still be needed. Its focus will be changed from harassing hard working tax payers to uncovering people that commit fraud. This will be covered in my newest section. Tax School 103 "Fraud".
> I think the IRS will have to go away, there is just too much bad karma associated with the name. The Treasury depatment will replace it with a new agency. Keep in mind that enforcement will now be in the States duties. The Treasury could run the entire U.S. sales tax system with a couple of clerks on a lap top computer.