Alex, I think there should be a "plan B" as well, based on a smaller number of takers.
I have been involved in making these sorts of arrangements for an Internet group in the past, with decidedly mixed results. ( I did, however, find my dear wife in the process!! ;-) )
If it's solely dependent on getting 15 or 20 takers, it might end up busting out.
AB, we can make it with less, I don't care and don't mind...but at least lets see if we get a few...
I will get in touch with him and find out what would be the cost for say 5 days, then I'll add the lunch cost etc..and we can come up with a final $ value per person.
But I am trying to avoid going thru all the trouble, and talk to people if I don't get enough people here to do it..at this stage I am only trying to see if we could have a decent number of people.
Please, if you people don't want to do it or can't, please refrain from posting stuff like:
Hey good idea...but I can't go....
I am serious about this, ok?