Despite the preconceptions you may carry to Sofia about the inability to buy anything except mouldy bread and copied CDs in the shops when you get there, in recent years, more and more western style department stores and shopping malls have opened their doors across the city including the former government store TsUM, which has been facelifted and massively improved making the city a pretty good place to go shopping for both souvenirs, and frivolities like designer clothes.
Prices are around the same as you would find in the rest of Europe in the newer shops, but you can get really good deals on things like Russian Dolls and wood carvings in the markets and back streets where the locals shop.
Bulgarian wine is very good value in the city as you would expect, and the best is the Melnik variety. The best place to shop for wine and other local delicacies is the Austrian Billa on Bulgaria Boulevard close to the city centre.