If you realize that your item will be distributed and sold through the usual wholesale or may be the retail channels, you should then definitely consider paying the additional cost for the bar codes. The barcodes that are generally used in sales and marketing come in two different formats- one is the EAN13 and the other is the UPC-A. The first one is common. The second one has the advantage of being readable in most of the places in Europe and USA. But the EAN13 is more generic to the European market.