They do it to get suckers like me buying the same material over and over again throughout the decades. For instance, 'Kind of Blue'. I've owned it on LP, cassette, first CD release, corrected CD release, Legacy Edition 2-CD release, metal spine MIles-Coltrane box set, and now in this big box. 'Bitches Brew' I've owned on LP, cassette, CD, 3 disc anniversary edition, 4 disc anniversary edition, metal spine complete box set, and now this big box. And so on. And so forth.