The fact that they are able to contend with much more expensive units when slightly cheaper ones are blown absolutely out of the water compared to volks makes me believe they are extremely cost effecient. For 250mp you get the ability to deny cover, snare vehicles and build cover, add stgs to the mix and it improves their long range dps (up a ways o don't recall who tested volks vs many units at various ranges and they did very well at long range but lost out up close generally) and uncontestable up close, while being able to upgrade in enemy territory with undroppable weapons. At vet 1 they get a 10% target size reduction making them more durable than rifles, after only a single vet (rifles cost 30mp more and will not scale without additional fuel and manpower) At max vet they even self heal.
For 250mp.
im 100 % sure rifle can contend with pgren at long range does it make them ultra super duper coste effective ? i mean pgreen cost 40 more mp and comes later
at vet 2 rifle get uber vet volks will only dream of it
again if the problem are stg change those not volks cost or dps