Officially renouncing your (US) citizenship when you can't afford the cost is not the way to go. If you really mean to "check out", just get on a plane and say

Officially renouncing your (US) citizenship when you can't afford the cost is not the way to go. If you really mean to "check out", just get on a plane and say, "see yah later, 'gator". No one is going to come to Serbia to harass you about not paying taxes.