I honestly wouldn't have predicted it, but it does hew to the idea that they're saving it up to spend on hammering President Obama. Via Taegan-
"Even as experts predict that the 2012 presidential race will be the most expensive in U.S. history, a funny thing is happening on the way to the Republican nomination: It's becoming one of the cheapest primaries in a more than a decade," Bloomberg reports.
"The top nine Republican candidates spent $53 million through September, compared with $132 million spent at the same time four years ago. The sum is even lower than totals reported during the same period in the 2004 and 2000 primaries -- when most candidates still were abiding by campaign spending limits in order to receive public matching money."