I bought Sketchup Pro a couple of years ago while it was still with Google. I am not sure what my upgrade situation is. Do I have free upgrade privileges to Sketchup Pro now that it is with Trimble? I have Layout version 3 and Sketchup version 8. If I upgrade Sketchup, will I be able to send my files to the Layout version I do have?
Checkout this Help Article, I think you will need to upgrade but it will only be about $150 if I understand the upgrade policy correctly.
You should just email Trimble directly so they can lookup your serial number and give you an accurate upgrade cost.