When my friend saw AVENUE Q there was a BC/EFA auction at the end of the show for a backstage tour and 6 windowcards (2 of each) signed by the entire original cast, understudies & swings. Well his mom & aunt enjoyed the show so much they were determined to win, and they did so for $1000 (which is easier on the pocket when it's for charity) they got the completly exclusive, touch-all-ya-want, stand-on-the-stage, full cast-led tour. They let them touch whatever they wanted, they played with the "Purpose" boxes, saw Lucy's boobs, toured the Green & Dressing rooms, stood on the stage & walked all though the sets and got to talk a lot with the entire cast, understudies, swings, crew, etc and had them all sign playbills, posters and cute t-shirts they gave them that you can't buy that have the Bad Idea Bears on them. I guess it really depends on the mood of the tour what you can and can't do. Just imagine if you were on that tour and follwed the "rules" stated above how much you would've missed out on.
And the moral of the story is: I got one of the windowcards!!