Your cost will vary greatly depending on your planning. If you buy food in bigger towns, generally cost will be lower, but tiny gas station/stores less options and higher prices. If you make you "care packages" ie food stuffs, bike parts, tubes, tires etc and have someone send them to you along the way to post offfices. Camping as said can be costly. Maybe send email/letters asking to spend the night to potential towns, ppl will offend invite you in the the night, feed you and letting you do landry.