We have been renting near Sandanski from a British person; a three bedroom house, fully furnished with all mod cons. Sadly, we probably eat and drink a little more than we should and would eat out at least twice a week. We have also spent some time living in decent hotels and driving a fair bit and I would find it difficult to spend €2000 per month but if you are in one of the cities where entertainment costs twice what it does in more rural areas and all of your shopping is from expensive supermarkets like Lidl you will spend more.
As to the area, I know nothing of the locality you are interested in but I would echo the warning about real estate agents. The criteria you use to choose a location are possibly very different to ours and perhaps also to those of other who will give advice here but my view and it is wholly my own is that the best weather in Bulgaria is to be found around Sandanski in the west or Ivaylovgrad in the east.
Sandanski has the advantage of easy access to a western lifestyle, plenty of shops and supermarkets and easy access to services but being just over an hour from Sofia it is popular with the Bulgarian middle class and this, allied to demand from ex-pats has pushed prices up. A three bedroom house in a village, of decent quality and with some land will cost €90k - €120k and a renovation project will cost anything from €25k - €60k. At the other end of the country life is simpler, Sofia is too far away to influence prices and the Black Sea coast just far enough away to avoid the Russian invasion. Services are slightly more difficult to access and life is very rural but a three bedroom house is unlikely to cost more than €75k and decent renovation projects can still be bought for €5k.
If you are coming to Bulgaria to enjoy a simpler lifestyle and accept a challenge the Bulgarian villagers will delight you with their warmth, hospitality and an open-hearted generosity lost to the UK half a century ago. If you want Iceland and Lidl with the prospect of Tesco just around the corner, a cosy community of ex-pats who rarely interact with the local population then I hear Spain is having a fire-sale.