The special workstation-only upgrade at $149 isn't available during the pre-release period. Unfortunately it will not be possible to downgrade you to the $149 special later. If you would like to buy the special workstation-only upgrade at $149 then please wait until final release day. Remember that there are additional benefits to buying the full $199 upgrade - it allows you to render on additional computers, not just one at a time. The exact number of render licenses depends on which edition you are buying. Terragen 3 Professional gives you 3 additional render licenses so you can render on up to 4 computers at a time, and Terragen 3 Professional with Animation gives you 5 additional render licenses so you can render on up to 6 computers at a time.