Fully vetted OSA AKM shoots entire volleys of missiles into enemy with very high ROF and with good ACC. Cost something like 80p and is very fast, poor armor though.
KUB-M1 costs 85p I think. But it gets a huge range bonus for 5 points and doesn't need any vet to make it a worthwhile sharpshooter. That high rate of fire might be useful for taking out helicopter swarms (spam) though.
Kinda disturbs me that SAM units get such a high HE power but when their missiles miss, they just fly off into space, the HE power doesn't come into affect. Only when the missile hits does the HE power have any chance to do some area damage. I don't think most modern missiles even have to make contact before exploding, they just have to get close. I'm kind of digressing here, I know the units who really do area damage are the AA guns.
Also yes, ammo does seem to be highly overvalued. I also find it weird how helicopter ammo is undervalued, and most huge price spikes from helicopter to helicopter come when the accuracy of the rocket pod changes but its ammo drops.