Just been reading dis
www.aviationexplorer.com...
Seriously, F-15s should be navalised, The A/B models $27M C/D $29M when the JSF is $39m and the super hornet around $50m.
Being like the tomcat but more advanced, faster, more manouverable, and has been exported worldwide.

Modern Eagles go for around $70m out of the factory. A navalized version would be much, much more expensive as the whole frame would have be
redesigned and strengthened not to mention redesigning the landing gear and electronics.
The added weight from the frame strengthening would make the aircraft slower, less manueverable, and heavier. The Tomcat was much more suited to the
carrier life than the Eagle.
Its obviously led to the F-22, Not only by the airframe but VT nozzles were first tested on it. Could make a decent bargain ATF for countries who want
somthing like the F-22.

Again the cost and limited upgradability would turn potential buyers around. If a country wanted to look for a new air-superiority fighter they'd be
looking at a cheaper Flanker model or a Typhoon that has more capabilities and future potential.