Its great to take a year off, and see all those countries on $22k, and if you're considering doing that, I highly recommend doing something like what he's doing!
For us, we chose to make international living more of a lifestyle. We are running our startup this way. When we added our third co-founder, it became three of us traveling this way. It is working out pretty well. We use AirBnB or local real estate agents to book accommodations. We stay in a country for 3-6 months depending on their visa length.
We work a sort of regular schedule, so we're not out seeing tourist sites every day. But that's what we do on the weekends.
At the end of the day, living like this, all over the world, is cheaper than it would have been if we'd just stayed on the West Coast of the USA. Well, cheaper financially.
One way we keep things cheap is by trying to focus on inexpensive countries. Our time in europe was great, but even there we stayed in berlin (which since the wall came down still has reasonably priced rents), and a small UK town. Mostly we're focusing on less developed / expensive countries which is also the more interesting ones.
We book maybe 1-2 flights a year. We are careful about this. We got a nice 7 day "vacation" in Venice when we were able to save $300 by booking a layover thru that part of Italy on our repositioning trip. Taking your time on your flights lets you maximize flexibility and gives you great opportunities like Venice. Keeping major international flights to a minimum keeps our expenses low.
All three of us live out of big suitcases. We were trying the "one bag one world" thing and living out of a 55 Liter backpack. This was ok in terms of size, but airlines have decided that refusing to take bags, even if they're carryon size, is a revenue opportunity, so rather than fight them, or deal with the hassle, we've switched to a 2 bag solution- one carry on for the expensive electronics and one checked bag for the clothes etc. (so 2 bags each, though the carry ons tend to be rather small.)
I really need to do a blog post about this. Actually, I have a dozen blog posts, but I need the blog first. And the blog is not coming until the MVP is done.
Anyway, traveling around the world for a year-- totally good idea, not that unreasonably expensive, and if you want to make a lifestyle out of it, you can do it, by increasing the amount of time you spend in each country to bring the costs down.
Only downside of living this way: there's some impact on productivity due to the travel. So, we lose probably 4-6 weeks a year of productive time because of it. For instance, we didn't get a damn thing done in Venice. Some of those "lost" weeks are the most fun too.