The version on the Marketplace is exactly the same as the one we have on sale here.
There's no way to manage products bought on the Marketplace with the FSDT Installer/Updater, since they are encrypted, so we can't change any files there, and there's also no way to convert a Markeplace product into a product bought directly, both because Microsoft doesn't provide any way to verify a license or share any data about their customers but, even assuming they would ( they will never do that ), such operation won't surely be free, assuming it was possible ( it's not ), because we paid Microsoft a fee to let you buy a product there, and we pay *another* fee to use OUR licensing system so, at minimum, you would have to pay some kind of fee to "upgrade" a Marketplace purchase.
But this is of course completely useless to discuss, since Microsoft doesn't have any way to verify a purchase happened on their system.
