If you do not need a job, can support yourself and your hobby and noting your preference, Ukraine would be a good choice in terms of quality price. With a budget of 500, I assume you want at least 5 shots per month and maybe up to 12-15 if short time.
But if you do not speak Russian or Ukrainian, it could be tricky to get the best deals unless you find a local wingman. Less the case in Hungary or Czechia where English is spoken in the bigger cities but then the prices are a bit higher. Also depends on what you want to do between punts as the cheaper spots will be less interesting places to be.
If it were me, I would head to Asia; Philippines, Thailand or neighbouring countries or Colombia or Brazil. But ok that reflects also my preference. There the living costs, once you get there, are lower allowing you more bang for your buck.
