Never, ever, start a job without agreeing terms. If they agree, great. If they don’t, also great - you avoided a situation like this.
We are always too scared to address prices and terms and it shouldn’t be that way. It’s always good to get things clear from the start, then it can all go smoothly, or you can agree to negotiate, or you can agree that you aren’t a good fit for their needs.
Always, always, always, get agreement on the rates , times, deliverables, what’s acceptable and what’s not before you do any job.
Chalk this up and accept the €100. But not the dinner, that’s just condescending and insulting for them even to offer. Photographers are doing a job, not begging for food.
Jamie Windsor is excellent - he is operating at a far higher level of quality and creativity than anyone else out there, in my opinion.