Quoted from cfh:

We all talked about this last night and came up with some limits/ideas.
we want to make it a 100 people max event. any more and it's just too much work and too much stress on our people. we like to make it comfortable but not stressful.
so how do you limit it to 100? can't really just say, "first 100 in and turn others away." That's unfair to someone that drove a hour to get there.
I don't like the RSVP system because people will just RSVP and then not show. Because they have no skin in the game. When this happens it locks out someone that really wanted to come.
So using the paypal inventory cart system, i can put a limit of 100 ticket at some dollar amount. this means you bought a ticket (skin in the game), and chances are good they will show up. So we kill two birds with that stone, in that i can limit the event to say 100 people, and chances are excellent that most (all?) will show up.
The down side is is of course if you don't have a credit card (i'm not sure anyone doesn't have a visa/mastercard??), they can't attend. But that's a pretty limited downside. And i guess an email to me could solve that problem if someone really had no paypal or credit card.
Anyway that's the thinking on this... Comments?