I would never pay those prices for SFC 3. I have the copy I bought at release, three comps have refused to run it, no patches or tweaking will make it run, it crashes after ship creation or doesnt even initialize. Its a coaster.
Not that I mind, nor have I tried that hard, since SFC 3 largely abandoned many of the things that made EAW and OP great.
Military Fleets don't do customized component ships. Period. The best part of SFC, to me, was flying what you got, and playing to the strength and weakness of each ship. For me, SFC 3 failed at that point, giving in to the shinies crowd.