Hi everyone,
Chiming in here from the SketchUp team: it's very likely that the licenses in question here are not valid. A few folks on the forum have already mentioned the not-for-resale clause of SketchUp's end-user license agreement; to clarify, we can arrange for the transfer of a valid license upon request. However, in this case, we can't validate that they are valid SketchUp Pro licenses in the first place. I'm not saying at all that helinbak's intentions are malicious (in fact, his posts on this thread prove that he isn't), but I do want to give everyone a heads-up for when they see licenses like this in the future.
If anyone has questions about these licenses or how to transfer a valid license, please use contact the SketchUp Pro sales team here: http://support.google.com/sketchup/bin/request.py?contact_type=sales
Mark