Allowing Membership to Be Offered by Regular Admins

I have a client interested in setting up a multisite. He wants to be able to allow member sites to offer memberships to their individual sites. So would they need a plugin like Membership 2 Pro to be enabled for these sites or does multisite already offer something like this built in?

Or would Pro Sites be the best option for this since he also wants to be able to allow for monetization for the individual member sites?