Of course they also have to think about tech cost in terms of "cost efficiency". Most of upgrades for the Allies mainline inf. requires additional upgrade. You have to consider opportunity cost of that mp & fuel used.
Pip is correct in that in general you cant account tech cost to unit cost. As each tech has different subjective value between unlocking upgrades abilities and units.
However the exception here imo is that with molly and at nade tech no other units benifits from this and no other units can be unlocked with this. It only and soley benefits conscripts. It used to be even more expensive and seperated.
Only in this case it can be added to unit cost. 4 cons is meta 3 is close to being meta. Divide to cost by 4 and add up, then put in the 50 muni and 18mp for each 7th man and we have quite an if not the most expensive but fantastic main line squad in the late game.