I see plans with access to the Enterprise repos starting at €110/yr, and plans with 3 support tickets starting at €340. €1020 is the starting price for a plan with a 2hr SLA.
For non production purposes, you're probably fine to use the the "No subscription" repositories. They're an official thing, although their website seems to go out of it's way to not mention it.
You don't actually need a subscription to run Proxmox, it's FOSS software after all.
https://shop.proxmox.com/index.php?rp=/store/proxmox-ve-comm...