what is the cheapest for a nomad
source: I've been to almost every country in SEA at least 3x. (Brunei was once, never went to Timor-Leste).
Check the forex changes and rent prices if you don't believe me.
Harder to factor in is visa costs. Vietnam, you need to leave every 90 days. So you need to buy a $25usd visa + flights/buses + hotels for 3-5 days while you get your next visa. Thailand, you only need to leave every 6mo on the DTV.
It's pretty easy to spend a year in SEA without raising eyebrows at any border if you're willing to change countries somewhat often and don't mind AirAsia flights.
The problem for me personally is this life is stressful on relationships, health, and personal productivity. Spending a weekend every 1-2 months to deal with travel (and arrangements) is exhausting and expensive on productivity hours.