Mado - if you browse this fourm, you will see how most of the cheaper media compares (burn wise), and lasts compared to more expensive media. You do not have to purchase TY or Verbatum's to get good media, even great, but if you want to minimise any risk and not waste money, mid-range trusted media all the way to top media is the way to go.
Those selling copies of things on to friends or the general public (game copies, film copies, etc, will not care how good the media is or how long it will last). Those spending money on ISP's, hardware, media, to backup data important to them will want their outlay and effort to last for quite some time - not last 6-18 months and throw away.
There are hundreds of reports on here from users all over the world, with a large range of drives and firmware - whereby the statistics (and scans) show just how variable brands such as Ritek can be (especially lower grade stuff shipped to Europe), and other cheap media such as 'colour-tops', 'bulkpaq', etc - well, some are almost bin fodder. Much of this is sold by formerly respectable stores - who have lost alot of custom. Not just me - all those who have gained wisdom, and are part of this forum, know exactly what's going on and why many shops are now selling junk - not much cheaper than quality media.