My point of posting the few deals I found is to suggest you dont have to group together with others to secure a better deal, as it can be done as an individual.
I think grouping together with others would inevitably get you a better deal but logistically would be almost impossible, due to data protection and all the other negative points that are on this thread, most of which are valid. The only way would be to set up a consortium- which would be time consuming stressful and dare I say what disabled people would not want to undertake.