Well hi Roy (& Laurie), your FIRST POST! How's your back doing, able to get back into boating now?
As you probably read, I did the trip from Los Angeles to Miami (Key Biscayne actually) in 2000 pulling a 31 ft trimaran. Average mpg was 10, same with my CD25 now. Figure 3,000 miles and 5 days each way. 600 gallons RT, at $3.00 per gallon (may be higher real soon though), that's $1,800 travel + meals (sleep on boat). Possible expenses along the way depending on the condition of your tow vehicle and boat trailer. You can use this to bounce against freight quotes for the boat + your airfare + hotel (waiting for your boat possibly) + taxi/bus expenses.
When I go again, I plan on about 300-400 miles of travelling around by boat, so add another 80-130 gallons for the boat depending on mpg.
You may have already figured all this, just thought I'd say hi.