its [sic] still wasn't operational so how much was it going to cost?
It wasn't operational yet because the previous Govt decided in 2009 to slow its entry into service. From the statements by people who claim to know about these things, in the short term, scrapping the aircraft will cost more than it would have cost to introduce them and operate them. And let's not forget the cost of using the various alternatives to provide some of the Nimrod's capabilities...