Hey there,
I'm very much interested in learning to ski off-piste. I found this: http://www.guideverbier.com/page-en-1-Off-piste-skiing.html
My understanding is that its a full day event. It would be ideal if we were 7 people, so we'd pay 135 CHF each.
If you are also tempted by the powder snow, reply here. When we are enough people we can arrange one day in Verbier...