What do you need it to do and at what risk to the crew?
If you JUST need an aircraft to find low tech Isis types and lob SDB's or brimstones at them then a modified biz jet will do the job for far far less than a Tornado or F16.
BUT
If isis gets some help with AA kit the crew of the biz jet are dead meat. ( protection just puts the cost up and the utility down)
To me the risk would be lower than that run by ground troops and there for acceptable but it's not me who has to sit in the biz jet.
PLUS
Western airforces have been reluctant to by kit only useful in very low end conflicts.
Last edited by boxmover; 6th Aug 2015 at 15:50.
Reason: Can't type