I'm Italian and you made the right choice to mention wealthy expats, as lots of retirees are emigrating to get higher pensions! To complement your article:
Portugal offers the first 10 years tax free on foreign pensions;
Canary Islands in Spain have lower taxes plus no VAT on alcohol and cigarettes. Plus the best climate in the world, according to Syracuse University;
Bulgaria because there are little taxes and even in Sofia everything is dirt cheap. From my own personal experience I've seen places make coffee for 15 eurocents and vodka shots for 70 cents in the centre of Sofia, which I remind you is the capital!
Thanks for the feedback @borederedge. Good to know this.