How much do votes cost?

This recent Washington Post column by Dana Milbank summarizes the "many backroom deals that were made to buy, er, secure the 60 votes needed to "invoke cloture" -- the legislative term for cutting off debate and holding a final vote." The bill itself has acquired the nickname "Cash for Cloture", while several of the provisions in the bill have their own nicknames:

Louisiana Purchase
Cornhusker Kickback
U Con
Bayh Off
Gator Aid
Handout Montana

So, how does one calculate the cost of buying these votes to the taxpayer? Is it merely the sum of these provisions, or is it the cost of the entire bill, which likely would not pass without them?