Yes, there is a difference in price and you have different plans to choose from and I’ll explain workstations VS servers.
Workstations
https://www.microsoft.com/en-us/security/business/endpoint-security/microsoft-defender-endpoint
With that link you will see there are two different Defender plans (P1 & P2).
The P1 plan focuses on Prevention and the P2 plan focuses on advanced detection and response. You will see that a M365 E5 license includes the P2 plan. If budget is a key factor you can get creative and obtain the M365 E3 license and use the E5 Security Add-on which includes defender plan 2. (You loose audit and a few other things so review the full comparison chart) - https://go.microsoft.com/fwlink/p/?LinkID=2139145&clcid=0x409&culture=en-us&country=us
Here is the link to review the different Enterprise plans: https://www.microsoft.com/en-us/microsoft-365/enterprise/microsoft365-plans-and-pricing
Something to note If your business is not at the Enterprise level then you can leverage a Business Premium plan. This plan does not include Defender for Endpoint but would include Defender for Business. Which is packed with solid EDR/AV needs, however you will find when you stack it against the enterprise packages that focus on security there is a large difference. In the Enterprise space there are more things to protect which is why you will see Microsoft XDR capabilities featured in the enterprise security plans.
Servers
Licensing is charged per hour instead of per seat, lowering costs by protecting machines only when they're in use.
https://learn.microsoft.com/en-us/azure/defender-for-cloud/plan-defender-for-servers-select-plan
With that link you will see there are two different Defender for servers plans (P1 & P2).
The P1 plan is very basic and the price is set around ~$5/server/month. The P2 plan has all of the bells and whistles and is set around ~$15/server/month. Defender for Servers covers licensing for Defender for Endpoint.
*note - Defender for Servers is one of the paid plans provided by Microsoft Defender for Cloud.
*note - Azure Arc helps you onboard Amazon Web Services (AWS), Google Cloud Platform (GCP), and on-premises machines to Azure. Defender for Cloud uses Azure Arc to protect non-Azure machines. To connect your non-Azure machines via Azure Arc, see Connect your non-Azure machines to Microsoft Defender for Cloud with Azure Arc.