Just realized that you could park in Walmart lots sometimes to save as long as water and sewage weren't a problem. Also, you can pick up a pretty decent RV for cheap this time of year according to Craigslist. And some of the medium sized RV's with 454's and such list 8-10 mpg instead of 4 mpg, Hmmm? At 8 mpg the RV fuel costs would drop $400. So it's beginning to look like if you bought a cheap RV with decent fuel economy, 4 people might be able to make this trip on a shoestring budget (read fewer events and less eating out) for maybe $3500.
Apparently you can't edit your comments?! I have counted the events that would likely be visited that would require payment for entry (aren't government buildings free, i.e. the monuments and capitol buildings?). I count 21 events at the estimated $80 for an event total of $1680 instead of $3300.
This adjustment indicates that the trip could cost around $4600.
This adjustment indicates that the trip could cost around $4600.