Ten or twenty bucks worth of food (noodles, tuna, gorp, clifbars). Lightweight camping gear I already had. Guerilla camping. Large meal at a family coutry style diner/restaurant $15. Minty Raleigh Alyeska from eBay: about ~$350.

Daily cost can be $20. Mostly food, fuel, and stealth.

If you're doing motels and campgrounds, then call ahead, plan your itinerary, and calculate.