YavorThe K240 sels for only $55 to $70. Since when are crappy headphones like these used in studios? Reproduction equipment in studios is always of the very highest accuracy. You don't get any form of accuracy in this price range, IMO.
BiffsBizStudios don't just use the $1500 headphones, they use a range of equipment from mid-fi to hi-fi. Any half-decent studio should be able to mix and test their mastering on a wide range of outputs so that they sound as good as they possibly can on as much equipment as possible. These are very good headphones for their price.