The renewal argument is often a spreadsheet. Broadcom quotes for on-prem estates are usually per core, often with a 72-core minimum. kcore is per physical CPU socket per year, not per core. Enterprise has an 8-socket minimum. Community Edition is Apache-2.0 with no subscription: the evaluation ISO and kctl are on GitHub Releases.
What you are comparing
A per-core price with a high minimum and a per-socket price are not the same unit. Convert both to a yearly figure for the hosts you actually own before you argue about features. A 16-core socket counted sixteen times is a different bill from that socket counted once.
Public list prices people use as a band, not as your quote: Proxmox VE Premium is about €1,100 per socket per year with 24/7 and a 2-hour Severity-1 target, Standard about €550. Vates XCP-ng Enterprise is about $1,800 per host per year. kcore Enterprise is priced to sit in that band. Custom SLAs are by quote. Check the pricing page and the other vendor's current list before you paste a number into a board slide. Those figures move.
What the subscription buys
The open-source core stays Apache-2.0. Subscriptions pay for official signed ISOs, the enterprise update channel, tested production releases, and support by tier. They do not change the licence on the public source tree. Standard is production support with a ticket cap and a business-day response. Premium adds unlimited tickets, a faster business-day response, and remote support. Enterprise adds a 24/7 Severity-1 response target of 2 hours, a named contact, and an 8-socket minimum.
Production clusters should run the same tier on every node.
What the price does not include
Electricity, disks, and the migration project. Early work is often services-led. The per-socket subscription is the long-term tail, not the whole engagement. Windows guest licences are still Microsoft's. A GPU is still one card per VM.
If the spreadsheet only shows the hypervisor line, add the migration line before you call it cheaper.
Questions: team@tacconiconsulting.com.