I've spent meaningful time in each of Thailand, Vietnam, Indonesia, and the Philippines trying to answer the classic question: which is cheapest and which is best value for money.

Thailand: The most developed tourist infrastructure at the budget level. Hostels are comfortable, transport is easy, food is excellent and cheap. You can do Chiang Mai on $25/day comfortably. The south islands (Koh Samui, Koh Phi Phi) are significantly pricier. Bangkok is genuinely affordable if you stay away from Khao San Road and eat Thai food. Overall: easiest entry point, not the cheapest.

Vietnam: The best value for money of the four. Hoi An at $20/day is achievable and feels like a good life. Hanoi and Ho Chi Minh City are slightly pricier in accommodation but cheaper for food. The north (Sapa, Ha Giang) is both beautiful and inexpensive. The overnight sleeper buses are excellent. Overall: best value, steeper learning curve than Thailand.

Indonesia (Bali focus): Bali has bifurcated. Canggu and Seminyak cater to digital nomads at $60-80/day. Ubud is more moderate at $35-45/day. But the outer islands — Lombok, Flores, Komodo area — are genuinely cheap if you get off the beaten path. Worth doing Indonesia if you can get past Bali.

Philippines: The cheapest island-hopping possible anywhere in the world. Palawan is stunning and if you time the boats right you can do multiple islands for almost nothing. The challenge is that inter-island transport is the cost driver — slow boats between islands can be $20-40 per leg.