Recently many websites, including massdrop, had huge discount on t1. After that, Beyerdynamic announced 2nd generation of t1 with detachable cable, and some material changes. This probably means there will be 2nd version of t90 also.
JuhanThat's very plausible.
Though it's usually when a new model comes out that you can get the old one for a song. Love my T1's (scored them for $512)