After traveling extensively for years, I've come to conclusion that all countries are shitholes. ALL OF THEM - except for Spain which isn't a shithole, but agujero de mierda.
The general level of most things in Bulgaria is relatively low. The good news is, prices are even lower. For example, some years ago I paid 450€/month rent +about 50€ for utilities for a 80-90 m2 apartment in Sofia. A quiet but central location, two balconies, a floor with Italian tiles, a great kitchen and good furniture. I haven't been able to find as good price/quality ratio ever since. In Cyprus you would be paying over 1000 €/month for a similar apartment. Perhaps equally good price/quality could be found in some places in Thailand, but that country is infested with tropical insects, lizards and transvestites.
Sofia is good for relatively low income earners, giving a lot of bang for the buck. The Black Sea coast I would not consider for year around living. I suggest people earning >100K (€/$) should consider some other country. Spanish/Italian/French speakers, if they absolutely want to live in the Balkans, could try out Bucharest. It is like Sofia, but prettier. Slavic language speakers have a head start in Bulgaria.
It is too bad that European low tax residence options are so limited. I don't think I could last long in a place like Andorra. It is a shithole with mountain views. Georgia HNWI is an option, but it is a shithole, too. A place like Estonia is an e-Shithole, and not even low tax. Gibraltar? An expensive shithole-on-a-rock.