Speaking about the Black Sea, one cannot but remember about Georgia. A beautiful, inexpensive and close country,
with an amazing history, and also very convenient in terms of logistics. You can either fly by plane from Moscow, or take the «Komete» from Sochi by sea. You can also get there from Vladikavkaz by your own car https://flytravelling.com/. Prices within the country, as already mentioned, are quite reasonable, a visa is not needed, and Georgian cuisine is a full-fledged attraction and cultural heritage of Georgia!
Of the obvious advantages of a vacation in Bulgaria, we can name the following: a close and inexpensive flight, simpler (compared to Schengen) visa rules, domestic prices are lower, and the hotel base is cheaper than Western European countries. Here you can add a loyal attitude towards Russians, a good climate and a huge number of ancient sights — in terms of the number of various monuments from Roman times, Bulgaria is in third place in Europe. Well, the beaches in Bulgaria are perhaps the best on the Black Sea.