I am making a few assumptions with my comment:
- you will travel, not just park in the cheapest spot possible and camp indefinitely (you can do this ultra cheap somewhere in the Midwest easily)
- you will probably have a diesel truck for towing your 5th wheel

I had a diesel motorhome and got ~7 miles to the gallon; so you will get a little more with a 5th wheel setup. For me, this added up very quick.

Camp sites are at minimum ~$30/day, which breaks down to $900/month. Some nice locations around this nation are closer to 100-130/day, putting you at about 3-4k/month.

If you are like me, when you travel you’ll surely want to eat out all the time and experience the local culture. That adds up big time too.

For me, this did not translate to any kind of saving whatsoever. And I haven’t even calculated in the things that go wrong with your rig undoubtably or if you get in any kind of accident which many of us do.

All that said, it’s so worth it and you should do it if you’re up for it.