Well, in the interest of staying on topic..... I don't think Spamhaus is
selling the data (as you spammers in do do).
So far as I know, the data are supplied by volunteers and voluntary
offerings of victims of spam.
What the charge is for is to support the high-volume capable servers and
data links required to support commercial enterprises (like Barracuda)
who make money off of those data.
Somebody who actually knows what they are talking about can correct my
errors for me. People in the gored-ox group can remain silent.