I've put together a site (http://FCPeffects.com) for Motion users to sell their effects and templates to the growing number of Final Cut Pro X users. I made the site public last wednesday and already have been getting a ton of support from the FCPX community.
If you know and love Motion 5, this could be a great opportunity for you. Eventually, I'd like to make FCPeffects the authority for buying & selling affordable FCPX effects & templates (much like Envato has done with Video hive for After Effects templates). Each seller will have their own corner of the site where your customers and fans will be able to easily browse all your stuff if they'd like.
Let me know if you're interested in being a seller and I'll give you more information about the program. I look forward to hearing from you!