They have safety deposit boxes in most of the hotels. They are really safe, you have a key yourself and so does recpetion but you need both keys to gain access to the box.
Also the exchange rate is generally better in Bulgaria than you can get here so I would just take sterling and change it up as you need to.
pint bottles of heiniken 4 lev, bottle water 2 lev, vodka with mixer 3 or 4 lev, pizza 8 lev, i drank like mad and was spending about 70 or lev a nite, nothing basically, didnt eat much, food was pretty rough, dont eat the chicken at the ski centre