Switching device to a pro license

I have a pro license on a laptop, and a free license on a desktop. I think that it would be better to have both devices on the pro license. I tried to deactivate the free license and activate the pro license on the desktop, and I was directed to buy a new version for $34.95. Is that right? Am I missing some way to do this that would not require a new purchase?

If I deactivate the free license and activate the pro license on the desktop, and buy the new version, will I lose any of the emails on the desktop?