you can buy a pas for 21€. I think Soll has the biggest night ski area in austria( maybe even in europe or the world) something like 15km. A few good runs and the park is lite.
it's open from saturday to wednes day if I can remember correctly
I'm off to Ellmau in a few hours, but after a night of driving and a day of boarding, no night skiing for me, just pares skiing :D