Your brothers wrong. If all media was the same, they would all be the same price, if they gave the same quality. Its all down to the dye the company uses and how they spread it. Obviously the cheaper brands (ritek, tuffdisk) will give worse results as they have less quality control, however the more expensive brands (verbatim, ty) will have a longer life span. If you download nero cd/dvd speed, and click on disk quality, you will find that the cheaper disks will have more errors than the expensive disks.
I used to use ritek disks, which began to fail about three weeks after burning them. I would say just burn to the branded disks, as the price is usually only Â£4-Â£5 more, and will last about 40x longer than the cheap disks.