can you migrate SX200 licenses to 3300?
Not normally... There have been Migration Packages in the past, but I haven't seen one for years. Contact your Mitel rep for more details, but they are very different licensing, more like the old 3300 "device" licenses than the newer style licenses so I doubt there is much they can do. \
Knowing your questioning in the other group, if you are a dealer you should reach out to your inside sales rep as there are demo packages you can get that are fairly inexpensive compared to retail versions, but cannot be sold.