Camping in this economy

We are planning a mother of a trip, starting in LA & going to every corner of your country, across to Florida up to Maine, across to Vancouver & back to LA with a lot of weaving in-between over 6 months. Towing a 28foot TT with probably a 7/8 seater van (not purchased) & have allowed $1000 a week for fuel, food(we eat health conscious - not take out) & campsites. Does this seem reasonable? It's an open question with many variables I know but from Australia so have no idea!
This is excluding sight seeing & entry fee to attractions.