Excellent post Sabina. I find it interesting because cost of living is something that is ever evolving. When I first travelled to Thailand in 2001 it really was cheap; I remember paying a meal for 6 at a restaurant on Patong beach that cost $15. $15 for 6 that included beer!!! Anyone going to Phuket today will realize that's no longer possible.
You're in Chiang Mai where my mother's retired (been 10 years now). But she complains about too many people and too much pollution. She'll be moving full time to San Miguel de Allende this year. We're in Nong Khai, right on the Mekong, and its gorgeous - quiet and clean, with just enough of an expat population that guarantees some good restaurants and specialty grocery stores. Costs are comparable to what you'll find in Chiang Mai.
Prior to discovering Nong Khai we spent a month in both Bangkok and Hua Hin where cost of living much more expensive. I was surprised because things had changed so much in this region - when I was last in Thailand (2008) it was still relatively cheap. But Central/Southern Thailand no longer a cheap retirement or slow travel spot. As someone pointed out on my blog, Thailand gets double the