April in Bulgaria is great for knitter tourists. I'm sorry I didn't post this earlier; the "shout box" shows me someone could have used it. I was there this April during Passover, right before Easter. Hand knit folk socks and especially slippers galore sold in all the main tourist sites I visited: Rila (monastery), Melnik (Rozhen monastery), Plovdiv, Koprivishtitsa. Knit lace and handknit sweaters were pretty ubiquitous, too. I didn't see handknit items in Sofia either, but I bet if you ask at the Womens' Bazaar, they'd tell you where to find it.