Depends on the requirements. Is the purpose to learn virtualization management? Linux sysadmin stuff? Virtual networking + firewalls? For my purposes it’s all of the above and more.

Having said that, I have not had an ounce of trouble out of Intel NUC 12 Pro NUC12WSHv5. So for $1000 I’d start with that and add NVMe storage and max ram in my budget. Running ESXi 8.