In my mind, it makes more sense to plan a date before collecting money. As somebody else said, I am more than happy to pay out for this, but I'm not so happy about paying quite a large sum of money upfront, only to later find I can't attend the date.
Shall we tentatively plan for June 19th? That's the day between the art show and the rock show, so Amanda will definitely be in London, just depends if she has anything else planned. We could ask Eric if she'll be around that day?