At the risk of sounding like a Sally Struthers plea for donations, if you save $5 a day--the price of a cup of coffee at some locations--from now until June of next year you should be able to purchase the bike and gear suitable for self-contained trips.
And having done tours where I have gotten hotel rooms and eaten out on occasion I can tell you those costs can add up quickly, even in small towns. For example, back in '11 the GF and I got a room at the cheaper of the two places in Wisdom, MT, a small town on the TA route. With tax it was around $50/night. We could have camped for free. Also on the TA route: Jackson Hot Springs, 18 miles down the road, will cost you over $130/night for a cabin. Mountain Spirit Inn in Darby, MT will cost you about $80/night. Stayed at a cheap place in Hamilton, MT last year and paid about $63/night including tax. Dillon, MT looks to be even pricier. I recently got back from the Black Hills of SD. The one motel in the nowhere town of Edgemont wants $60/night plus tax. Camping at the municipal campground, with showers, was $10/night. I could have camped at the fairgrounds for free. If you spend even $20 more/night because you are staying in motels vs. camping, you are talking an additional $1,600 for an 80 day trip. (Unless you do a lot Warm Showers and Couch Surfing, I think that $20 figure is very conservative.) Again, shopping smartly, you could probably outfit yourself for the trip for that amount, if not less.
Then there is the issue of reservations. Many places are small and can fill up, especially during high season.