Thailand is still cheap compared to Europe, but there's a trap that people don't mention: prices in tourist areas like Bangkok and Phuket have gone up quite a bit more than in smaller towns or inland areas, so if you only stay in the gringo zone you end up paying almost like a mid-range destination in Latin America. What does work is mixing it up: spend a few days on the beach or in quieter towns where you can still get a decent lunch for 2-3 euros, and that brings down your trip's overall average. Hotels are still affordable if you don't go looking for unnecessary luxuries, but get into local forums to find recommendations that tourists don't see on Google, because the difference between paying 40 euros and 25 for the same quality is huge when you're traveling for a week.