(Timbo, I used your post for a model, hope you don't mind!)

Vehicle: 2003 Kawasaki ZR7S (750cc) Motorcycle
Passengers: Bob!
Length of Trip: 8 days
States traveled: 7
Miles covered: 3,097 (387 miles per day)
Avg. MPG: 56.25 (high 64, low 49)*

*The main factor in gasoline mileage was speed. The best mileage was obtained at 60-65 mph. The worst was a result of a somewhat higher speed on little used state roads in Colorado and Wyoming... the difference was about 28%.

Avg Lodging Cost: $54 (high $119, low $43)

Food: Avg $38.46 per day
($9.53 breakfast, $9.46 lunch, $19.50 supper)*

* I ate well.

Fuel: $137.20 ($17.15 per day)

I didn't track other costs; there was a small amount spent for gifts (less than $50 probably), and I used my National Parks Pass for park entrance fees at several sites (4). I also spent $322 on maintenance for the motorcycle and a new rear tire in South Dakota.

Total costs for the basics - $825. This was about $103 per day on the road.