Commercial Windows 10 Extended Security Updates started at $61 per device for Year One, and Microsoft’s published terms double the price every consecutive year, for a maximum of three years. ESU is also cumulative, so an organization enrolling in Year Two pays for Year One as well — each year of delay compounds the cost. If you still run Windows 10 PCs, weigh a Windows 11 refresh or Windows 365 against two more years of ESU; Windows 10 virtual machines in Windows 365, Azure Virtual Desktop, and Azure VMs get ESU at no additional cost. Confirm current per-device ESU pricing in your quote, as it varies by channel.
Source: Microsoft Learn — Windows 10 Extended Security Updates ↗