I've only ever done organised tours with the Elbow Valley Cycle Club, and I've done this tour twice (enjoyed it!):
http://www.elbowvalleycc.org/events/...p?eventid=1500
It's a 3-day Golden Triangle tour in the Canadian Rockies, and the price is $265/person, or $88.33/day which includes camping on a long weekend in the mountains, all your meals and snacks (and they do feed their riders well!), SAG support including carrying most of the gear, medical and mechanical support, T-shirt, and a chance of winning several prizes.
If you were to do the same 3-day tour in the Canadian Rockies on that long weekend, you'd be looking at a minimum of $30/night for accommodation (quite possibly as high as $40), plus about $10/meal = $30/day, plus $5 or $10 for snacks/day ... add that up and you're looking at $65 - $80/day. So $88.33/day for a supported tour isn't bad at all.
Like I said earlier, if you're looking for an organised tour, check out Cycletouring clubs and see what they've got on their schedule.