The expense of the LCS.

The Pentagon's Outdated Budget Priorities, Fred Kaplan for Slate, Dec 22nd, 2005

Nearly all the big-ticket items belong to the Air Force and the Navy. These services aren't experiencing much of a manpower crunch. (Few pilots or sea crews are being killed in Iraq or Afghanistan now.)
...
The Littoral Combat Ship: tripled, from the administration's request of $249 million for one ship to $689 million for three.

The Navy's major contribution to the Global War of Terror (other than flying sorties over Iraq and Afghanistan) is by patrolling sealanes looking for terrorists and WMD.

$689 million wouldn't buy even one DDG, which is what they're using now because the Navy didn't budget for very many small patrol craft during the Cold War or the Clinton holiday.

281 Deployable Battle Force Ships simply isn't enough and we can't afford to buy ships that are bigger than are needed for the job at hand.

And best of all the LCS carries a fourth the crew of a DDG which allows the Navy to cut total payroll, which is always the biggest lifecycle cost of any ship.

-HJC