I would happily come to Las Vegas, and pay around $300 for the right seminar with you and/or Erin.
What would make it most appealing to me would be:
-- mix of both Steve and Erin material, all in one long weekend
-- very experiential, rather than lecture/presentation based material
-- fun -- very important!
-- small group preferable, but not necessary
-- Erin: anything she wants to do is fine with me
-- Steve: I wouldn't be as interested in a general, top-down rehashing thing, since I've already devoured everything you've written, along with tons of other pd material. I would be more interested in a seminar aimed at folks who have some experience with this stuff under their belt. In other words: a challenge!
For both, physical moving around as much as possible would make me happy -- those seminars in which you sit in a chair for hours at a time are so last millenium.
I would also be interested in assisting you during your weekends, if you need someone to come out a day or two early for administration or facilitation of an event.