In the grand scheme of things, £80 million doesn't seem that much ( so please PM me for details of my account to send it to ).
I doubt there are many hangers-on in a Sentry, so how are the cost reductions as in less crew going to work unless the new no doubt VERY expensive - but essential - kit is fitted ?
Even with the fanciest kit, these things are up for long periods and people get tired - I doubt reducing crew is a sensible idea, except to accountants on the ground, and not even to them if looking ahead more than the next month, as such creatures tend to do.