It doesn't have to be a very high one though.

I quit my job and spent 2 years driving from Alaska to Argentina. I poked lava with a stick, paddled with icebergs, climbed a 20,000ft active volcano, surfed, etc. etc.

It cost $1,200 per month for absolutely every expense [1]

Before the trip I was earning $48k CAD (about $38k USD).. I just didn't spend much.

Later on I quit my job and spent three years driving all the way around Africa (35 countries around the perimeter, 54,000miles). I rode a camel and camped in the Sahara, I carried Chimpanzees, saw gorillas, petted a cheetah, saw tens of thousands of elephants in the wild, heard to lions roaring while sitting around the campfire, surfed, hiked, ate street food with friendly locals, etc. etc.

That trip cost about $1,650 per month for absolutely all expenses. [2]

Before that trip I was earning $72k CAD (about $57k USD). Again, I just tried hard to save and not spend much money while going to work for years)

I've met plenty of people that have driven their own vehicle to 100+ countries over a ~decade for about $1,500 a month. It doesn't have to be expensive.

Now I do this "for a living". I keep my expenses low and have adventures around the world. I just flew to Australia, and I'm preparing now to spend about 18 months driving all over to all the wild and remote corners I've heard about but have never seen.

[1] http://theroadchoseme.com/the-price-of-adventure

[2] https://www.youtube.com/watch?v=XeR3SncZkv0