Losing the E-3s to pay for them would be a good trade.
Whether or not the trade would be good is a moot point.
The fact is that whether or not we, as the RAF, operate them, we will continue to pay for them. At least with RAF roundels painted on the side we get some say in how they are used.
Blame NATO, blame the Govt, blame Brussels, blame Allah, it matters not, we pay for E3s whether based at Waddo or GK.