Try to follow the logic:
1: The Department of Defense submits a budget request in February, requesting to buy 12 JSFs -- 6 CTOL and 6 STOVL -- for $2.65 billion. (See page 26 here.)
2: The House Appropriations Committee passes its version of the defense budget on July 25. The lawmakers approve the Pentagon's exact request for 6 CTOL and 6 STOVL aircraft, which seems like good news for the program.
3: But there seems to be a catch. The House appropriators allocated only $2.41 billion to buy all 12 aircraft. That's $220 million less than the requested amount for the same quantity of aircraft, which is roughly the cost of one of the originally priced fighters.
4. So is it a typo, a clerical error? The guess here: no, it's a message. The House wants DOD to know that $2.6 billion is too much for 12 fighters, even at this early stage of the production program. The question is: will $2.4 billion really be enough, or is Lockheed going to get rolled?
[Full disclosure: a family member is a Lockheed Martin employee.]