I'm not a season ticket holder as I live too far away, and I'd love a black jersey, but if keeping them exclusively for season ticket holders gets more season tickets sold then that's a great move.
To stop people selling them on, how about the club personalises them with the STH's name and the year (15/16 season). They could charge a little more than that, and also offer to add the player's name and number with a personalised signature on the back for a little extra again.
To me, that would be a great perk of being an STH.