If you actually intend to freely license it, you will recover nothing of the cost.
The free license does not apply to patent aggressors, so we gain the ability to enforce against them which is very valuable. It's very rare that patents for cryptographic purposes actually generate their own revenue, their value (free license or not) is primarily defensive.
The true reason why BlockStream and others get patents yet pretend to take the high road, is because when they get a good one and the network moves in their direction, they'll be able to say: "Oooops, changed our mind. No more free licenses".
The licenses are irrevocable, were it not it wouldn't have been applauded by groups like the EFF.
Blockstream has made other movements which seem somewhat less than altruistic to me. I'd say be on guard with this one.
Oh really? Whats that?
OK-
So a company gets an irrevocable license from you. Then, after some time you unilaterally 'deem' them a 'patent aggressor'. What then? Do you revoke their irrevocable license? I thought so. So anytime you want to go after someone, just allege they are a 'patent aggressor'. Since there is no uniform means by which one can be discretely determined a 'patent aggressor' you can revoke anyone's license anytime.
The patent system is law in many countries. EFF is hostile to the law in a great many regards. I am sorry they don't like that law. But it does remain law and fair and good and noble, despite those terms 'troll' and 'evil' which the community likes to attach to patents.