DataUnison has a new free version of their eBay Research API, for non-commercial use.

"At its core, eBay has created an open marketplace for goods and services," says DataUnison CEO Fred Speckeen. "But it also enables market competition - an important capability. With these new and updated tools, DataUnison taps into eBay data to provide sellers and now developers with the most comprehensive information for their online businesses to compete effectively. Developers are critical to harnessing this information to enhance online buying and selling through eBay."

DataUnison is a licensed eBay Market Data reseller owned by AERS, the company behind research tool Terapeak. They also license an advanced set of APIs to get more comprehensive data. More information.