Of course the Zarses are happy to contribute towards costs and indeed we sponsored a barrel last year which I'm fairly sure we drank about six times over! BTW, I'm sure I remember Maruis keeping a pretty tight check on who'd paid for what and when. Maybe he later got staggeringly drunk, the record keeping went all to pieces and he went mad and decided to cut off his pony tail or something equally ridiculous!

who knows...
Anyway, I think the suggested "pay in advance" for a wristband concept has some inherent design flaws ( and you probably know about these).
1. - Crowd control. How do you know precisely who the wrist bands are going too or that they won't be passed on to someone else who may be a less than desireable invitee? Lets say, just as a "for example" a group who we know (such as The Twaits etc) order thirty bands. How can you be sure who they'd bring along if they'd over-ordered and had to sell some to recoup their money? You could end up with some Houx Annexe ruffians (and I mean the roundabout tossers, not the Cobrateers!) with supa-soakers and a bad attitude. I dare say we could all put them in their place if we had too, but none the less it would spoil the unique freedom and fun loving Dutch atmosphere that we all appreciate so much.
2. Legal liability aspects - you start charging in advance and you become a public event (regardless of the charity aspect). This calls into question the limits of liability. Let's say a drunkard tumbles off the scaffolding and breaks his neck. His wife, who may not have been that keen on his attendence at LM anyway decides to sue DfH. A whole word of grief for you guys there...
3. Licencing - Dunno about this but is an event licence requitred in France?
Just my thoughts anyway. Sorry to be the voice of doom here but please consider them before changing a sucessful formula.