Hi Serene,
These two threads
https://acusersforum.com/ub/ubbthreads.php/topics/74303/windows-7#Post74303https://acusersforum.com/ub/ubbthreads.php/topics/74463/re-windows-10-upgrade#Post74463discussed the issue in some detail.
Basically, most of our workstations are old. They have plenty of processing power, and usually the only part that is likely to fail with time is the hard drive. I purchased new solid-state drives, Samsung 500 GB, around $80 each. I plug the new drive into the work station, clone onto the new drive, then physically swap them. Then upgrade to Windows 10, which is still free, if upgrading from Windows 7 Pro.
Our office has done this, about a dozen computers, no problems. I did this for a nonprofit counseling center I am involved with, about ten computers for them, again no problems at all. And I know numerous posters on this board have done this.
Basically, I am cheap……
Gene