buying x4

Hi

I'd like to get back to using chief after many years since I last used it.
I have an opportunity to buy x4 from a colleague who no longer uses it.

He wants to sell it, but I need to know what is legitimate for transferring license to me and removing it from his computer?
If that's a possibility - what would be the upgrade price/policy to upgrade to x5 (or the next version)

Are there any other issues to consider?

Thanks for your help.

Your best to call CA directly and talk with them. Have the license number handy though. They have a streamlined transfer system that will make it easy.