I’m surprised that the ‘agency’ price is more than double the ‘business’ price.
In my experience of using verion 5:
Change notifications are interesting to keep an eye on clients - but not essential
Non of my clients care about white labelling. I tell them the CMS is Surreal.
So for me the only difference is the Developer API - which I would never use anyway.
** Is the version 7 white labelling as per version 5? Upload a logo, change the colour, using your own domain and a custom log in form? Or is there more to it?