It seems a punitive to have a half resell cost for equipment that is placed during the initial setup of a line. Perhaps allow equipment to be moved instead?
Good news - You already can! 
If you double click a machine on the factory floor, you will pick it right back up, allowing you to move it elsewhere at no cost (aside from new belts) - It’s even in the first? tutorial I believe.
Or if the machine is unused, perhaps, it could return full value, same with conveyors.
Yea that would be nice. I feel like i (idiotically) always place the wrong machine. I would rather just get rid of it than move it which adds clutter to my pharma.
I agree with being able to sell it for full value if unused.