Daniel,
For example, maybe their chef and cooking staff are permanent employees,
and they have to pay all the wages no matter what happens (unless all
those employees take annual leave during DebConf)
If their business model is really so rigid and inflexible, time spent
trying to negotiate may just be time wasted, time that could have been
spent finding alternatives.
Their yearly budget for 2012 for accomodation is CHF 750K and for food sales CHF 400K.
The current offer for food is about 25% of their annual food sales budget. And this only for 2 weeks.
So, I think there should be some flexibility on their side :-)
Philipp