Are the Nuxeo Hot-fixes free or do we need to pay for them ?
Technically, since Nuxeo is free and Open Source Community driven project, Hot-fixes should be free !
Incase the Hotfixes are not free, then
I believe you should only charge for the business support (phone and 1 day e-mail etc) and for customization through Nuxeo Studio which is fine but charging $3000 for Hot-fixes really seems questionable. Also, I would like to point out that any user who has searched for 'Free Document Management System' and has decided to use yours would be put off since by charging for hot-fixes it is not really free.