I think UPS is paying a good $16-18 million per year to be the primary sponser for Dale Jarrett, if that helps.
It goes something like this: $12 million and up for a proven frontrunner (such Penske, Ganassi, Yates), and $7-10 million for a mid-packer (such as Bill Davis, PE, or Petree). For someone like Brett Bodine or Junie Donleavy, $3-5 million would likely get you their hood and quarterpanels for the year. And that's just the primary sponsors. I believe associate sponsors pay about 15-25% that amount.
I read about this in a newspaper article a while back, but I can't for the life of me remember who wrote it.