Hi Angeli,
Serbian prices are horrible means at least EU * 1,3-1,5 , but there is an another option: Lots of your Serbian Friends are coming to Szeged (HU) and buying sets in a small official LEGO shop. They are authorized HU Dealer and they have the newest sets plus new and used bricks & accesories. They are speaking english and very much customer oriented. Surprise: they even have VAT refund form for Serbians !
You can contact them with the following link: http://www.letsgoszeged.hu/kapcsolat
Even members of skockani from serbia knows them...
regards_Rsy