For "coming down the pipeline" they're essentially free.
Today, the c910 is an Apache 2, hardware proven out of order core on GitHub here https://github.com/T-head-Semi/openc910 a little slower than an RPi3's core.
I think the point is, very few people are looking to buy some RTL, they want the silicon. So the question is what's the price of the silicon? My understanding is anything comparable to the SoC in the RPi boards is still quite a lot pricier.