An SMMR is 2 points more than a combi, one point for the superior range and one for the shock ammo seems about right. A multi rifle is 4 points more and has no range advantage, though the DA and Stun ARO options are very nice. Spitfire is 6 points, so triple the increase, no special ammo, and probably 1 SWC on this sort of platform. Definitely a better gun, but with the opportunity cost of SWC in an already SWC hungry faction. I'm not sure I can agree with "Way too expensive", if it was any cheaper you'd be paying the same or less as a combi when you take the ammo type into consideration.