From https://www.plasticscm.com/pricing under Licensing:
Team Edition License (deprecated)
Team Edition was available for teams of up to 15 users who need a central server in their office (or several servers). Team Edition allows you to checkin directly to the central on-premises server; no local server is needed (but you can use one).
Current Team Edition customers will continue to have support and upgrades, and they will be able to add/remove licenses, but no new Team Edition subscriptions will be sold.
The Cloud extension adds cloud functionality to Enterprise Edition. Cloud extension is a Plastic SCM server service which allows you to host your repositories online. You can push/pull (or directly check-in) to a cloud server. You can work with a Plastic SCM managed service plus on-demand cloud storage capacity.
For Team Edition, you pay $9.95 per user/month or $113 per user/year when paying online.
For Cloud Extension, you pay based on the storage capacity ($9.95/month per team for 15GB, $20/month per team for 100GB, and $7/month per team for each additional 50GB bucket).