I have the old "Made in Austria" K712's purchased 10 years ago, at a quite higher price. They are selling for 220€ here and i bought them for 340. They got cheaper but as everyone wrote before me, not on the spare parts. The pads are selling for 48€ per piece, that is 96€ for a pair.
I like them eq'd for vocals and choir and when i do not want pronounced bass. Without eq they just sound muffled. My big objection is, that even though they are super comfortable, the headband adjustment does not lock in the adjustment position and the phones are gradually slipping from the ears especially when you are moving -like "moving the faders on the console in front of you" type of moving-. I would not buy them today, due to the cost of pads and the headband issue, but if anyone looks for a headphone that shouts "fashionably smart" and "studio pro", at the same time, then look no further (poser!
).