One important note for US citizens, you still owe federal income tax even when permanently living abroad unless you renounce your citizenship. So while the taxes might be reasonable there, you still may owe the US too for the difference between what you pay there and what you would’ve paid here. It’s even more complicated if you are self-employed in another country. There’s a lot of nuances that I’m not qualified to cover, so I highly recommend talking to an accountant before taking the plunge.
My understanding is if you are able to claim the Foreign Earned Income Exclusion then you wouldn't owe any US Taxes (unless over the $103,900 for 2018), but haven't done this myself and agree that an accountant would need to be in the mix for US Citizens living overseas.
Some light reading:
https://www.expatinfodesk.com/expat-guide/nationality-specif...