With Nike and Adidas its a bit of a double edged word, because if your in the Champions League regularly and at the top end of the table, the club will get a big deal, but for the fans the shirts go up to £100 each.
If you are not in the champions league they would pay the club less than we get from Hummel and we would get a template kit and as we saw from Nike, (2012 to 2014) we often received our kits late because they prioritized other clubs and part of the reason we had the ugly 13/14 badge is because Nike wanted something easy and cheap to make.