However, after the costs of my flight and buying the gear I'll need I'd like to keep my travelling expenses below $50 a day. Does that sound do-able including perhaps a camp site with showers? On that topic, how much do US campsites cost on average for cyclists.
Sounds doable. You might want to read the Bike Touring 101 article on our How To page (http://www.adventurecycling.org/features/howto.cfm) for other tips and thoughts on cost.