My wife and I traveled full time for 2 years and 30,000 miles. The big cost was fuel @12 mpg and $4/g that was $10000. Maintenance was 5 oil changes and an additional $1k for major scheduled maintenance. In addition one tire was damaged and I replaced 2 tires. Total cost of maintenance for two years was about $2200.
I have a solar system and a backup generator which we also use for A/C on really hot days. We only stayed in RV parks twice in 2 years. A few times we stayed in State campgrounds with hookups. Travel nights were at Walmart or equivalent. Total campground costs averaged $7/night with the senior pass. A single propane tank lasts almost two months with daily showers, cooking and occasional use of the furnace. Another $10/month at most. Gas for the generator was another $5/month. Restaurants and admissions were maybe another $200/month. Admission to National Parks was free with the senior pass.
We toured the western US and Canadian rockies and still spent under $1000/month for travel, camping and entertainment. Plus we did not have to stay in crowded RV parks. Get rid of the big bloated RVs and the hook ups and you can travel and live at very low cost.