Besides...you can, in theory, shoot two targets at once with missiles...you select one and shoot at another. Whenever the selected one comes into the missiles' effective firing arc, pop your missile key while still shooting your other target with your guns. Note, that's in theory...it would take a little bit of higher awareness to actually pull that off repeatedly and effectively, but it IS a possiblility(one which I intend to test as far as I can when I get on FL today).
Reaper: $200,000,000.
Rockets: $100,000
The look on that pilot's face when you launch a full pod of screamers up his tailpipe: priceless