Just got back from Borovets and wasn't very impressed with the range of boots they have. Did see some Salomon boots that were a little bit cheaper than they would be in the UK. Alot of the boots seemed to be just a single boot rather than the outer/inner boot combination that gives a better fit. If you can wait for the sales here I would, I found some Burtun Ruler boots for £80 down from £150 in this country. Looks like you should have some good snow. Have a good holiday.
If you go up the town and take a right, where you will pass the Blue Bar there is a small shop on the left which sells HEAD and Salomon boots. About the best range we found in this resort.
I bought a pair of HEAD 1.80's there and they are very comfy boots with seperate inner boot which also has a thermal ability to mould to your feet.
Cost around 250 levs which is about £92 at a 2.7 rate. I have scanned the web and it appears £99+ is the going rate for these boots.