[cenal]

If you only need a single copy you are best suited buying from Microsoft directly.

If you need multiple copies you can work with a VAR (Value Added Reseller) to get better pricing.

CDW.com is the big name in VAR's but they have enormous turnover in staff. I try to build relationships with smaller VAR's. I like these guys: https://greenbeetech.com/ it's a small company with two guys running it who have decades of VAR experience (former CDW people).

Navigating the process of compliantly licensing Microsoft as you scale up is quite a job. Having a good partner to help your organization stay compliant is very valuable.