sB beat me on this one.
Indeed, Slovakia still only the 19% flat rate, would recommend a place right outside the city though...
Apart from that, cheap European cities all over Russia, Belarus and Ukraine, as well as Istanbul which are all very cheap to live (not sure on the taxes, though remember Istanbul to be low a couple of years ago). Istanbul is probably the only one apart from BTL where you wouldn't get a cultural shock...
You'll probably need to travel around a bit, as former Eastern Europe is not for everyone and the language barrier can be quite significant. Also depends on whether you bring family (British and American schools can be found almost everywhere, though pricey).