"So if I want to port it over to use in poser I need to get the more expensive one, makes sense."

Actually, no. Items without copy protection are not limited to use with any one particular Vue installation. So, if you have multiple Vue installations, buying the unencrypted version allows you to download once for all installs, rather than once for each of your registered installations.

That is a completely different thing from the ability to export to other 3D formats. Whether export is allowed or not is the descision of the artist who created the mesh involved.

Hope this clears up any misconceptions.