I'm currently sat in Salt and Peppers in Borovets and it's 3 lev £1.50 for a large beer, I've not paid more than 4 lev so far and most places have happy hour where most drinks are buy one get one free, cocktails are about £3-4 but are most of the time BOGOF so your getting 2 anyway. Plus to get you in most offer a free shot!