Actually, Markus, thanks. You gave me a reason to look through the lore and admit that I wasn't fully correct while referring to the Samura, Hogosha and GMG interests on the Artifacts market. Oh, no, let me rephrase:
I wasn't correct when talking of Samura and Hogosha. I can only refer to the vanilla rumors that state that the Hogosha controls the deals with them and those activities are ignored in exchange of doing what Samura don't want to do itself. But it doesn't change the point that the interests of all sides are there and that Samura dealing with the Corsairs directly is against Hogosha interests. Guild was booted out of the artifact dealings earlier. Sorry if the explanation is a bit tangled - I'm a tad exhausted at the moment.
Artifacts that come to Kusari? They are interesting for scientists and for collectors, therefore they head to the research facilities and are sold on the black market. Not like there are more opportunities.