You can only upgrade directly from Curious Labs, as our system is now. Things could change in the future... Here are the US upgrade prices from the CL website. INTERNATIONAL PRICING WILL VARY!!!!!!!! Upgrades to Poser 5 from previous versions of Poser are available at the following US$ prices direct from the Curious Labs web store. Purchase of the Poser 5 upgrade will require a valid Poser serial number, and you may only purchase one upgrade serial number. $209 - Poser 1, 2, 3 Mac or Win to Poser 5 Win $179 - Poser 4 Mac or Win to Poser 5 Win $129 - Poser 4 + Pro Pack Mac or Win to Poser 5 Win