I've driven cross-country (Michigan to California) with my family 3 times now in a motorhome! It's a wonderful experience. You can stop when you want, if you want. You can camp in a K-Mart parking lot if you need to (and we have!) But the gas mileage is horrific. On our first trip, we spent over a thousand dollars in gas alone. And that was in 1983. However, what you lose in gas money you just may make up by not having to stay in hotel rooms. But it's an awesome way to see the country. Depending on the time of year you plan to travel, you may need to reserve campsites, especially at the National Parks. I'm sure you can check the park websites for pricing information on sites. Map out a possible route, figure out the number of miles, approximate the cost for gas, and go from there. Another thing you need to think about is if you are going to tow a car or not. The downside of having your living space in your car is that you take it with you everywhere. So even if you just want to take a daytrip someplace, you may need to pack up. Let me know if you need any more info.
"Is ice hockey hard? I don't know, you tell me. We need to have the strength and power of a football player, the stamina of a marathon runner and the concentration of a brain surgeon. But, we need to put all this together while moving at high speeds on a cold and slippery surface while 5 other guys use clubs to try and kill us. Oh, yeah, did I mention that this whole time we're standing on blades 1/8 of an inch thick. Is ice hockey hard? I don't know, you tell me. Next question."