Yes, you are exactly right. I'd argue that if you value your employee's time at anything north of, say $10 per hour, then having a super-quality whiteboard would be a hugely positive ROI investment.
Think of it as a giant shared 3rd monitor. Would you buy monitors that ghosted if your programmers typed the "wrong" letter combinations?
...which works less each time around, and stinks, and uses paper towels, and takes a few minutes of wiping each time you want to get (close to) clean again.
Top-quality surfaces wipe back to bright white with a single swipe or two of the dry-eraser, even if the text has been up for weeks. They're worth it for many offices.
Think of it as a giant shared 3rd monitor. Would you buy monitors that ghosted if your programmers typed the "wrong" letter combinations?