-obelix-, I think it's not that Serbia is not in the EU, i think that the problem comes from the fact that we're just in Eastern Europe. Although Bulgaria is a EU member since 2007, the price of almost everything is higher than in Western Europe - electronics, toys, clothes, etc.
For instance Mircwood Elf Army here is 70$. And having in mind that the average wage in Bulgaria is so low (about 550$ a month), the lego prices are completely unacceptable.