Retiring in Ukraine

Hi all, just wondering if anyone can help with my question:
1. How much do I need to retire and live a comfortable life with my Ukrainian woman, (whom I've recently met)  in Kiev or Odessa?
2. What could I expect my monthly expenses to be to live a comfortable life if I buy an apartment for cash  in either of  the cities above?

For living costs try www.numbeo.com   Also read through other posts here too.