Internet: Getting more money ...??

Point may have been obscured. You add more facts (thanks!) the question is what
$10 million represented -- did it include the money IBM spent but did not charge
the NSF?

As for the NSS's being still in place but disconnected, I thought the lease
was up a year ago.
The NSS's certainly are not cost effective. One of the problems
that they faced in the versions subsequent to those you had at ANS was running
out of backplane bandwidth for WAN-LAN (and LAN-LAN) transfers. Another of course
was their proprietary nature.
The price tag doesn't surprise me, Rs/6ks are expensive. But the sampling
feature would be helpful in the SYN attack situation.