point is that as SU, you pay just for AT nade, where as OST you pay to be able to use Faust on your greens and osttruppens, but at same time, you are getting access to build 3 types of units....that is the difference....so, again, comparing cost of a side tech with cost of a tier is so funny and wrong.
And the point is that as Ostheer you pay weather you need the faust or not while as a Soviet you can chose when and if you want to get AT grenades.
And while we are at you have a problem with Ostheer getting their Faust in package deal, but you have no problem with Allied call in infantry that come with "tech free" grenades and "tech free" weapon upgrades while Ostheer have to research T2 get the same goodies for their call in units...
Think the majority of Ostheer players would rather have Faust, grenades, lms and Shreck as side techs if that allowed to have a non linear tech path allowing to invest their resources at they choose...even if it meant a bit higher price which is not actually the case since the total tech path of Soviet is cheaper.
Total cost of Osteer tech path is 830/290/60 (MP/fuel/MU) and of the Soviets 910/225(MP/Fuel).