5 model IS with upgrade are cheaper obers with more tools in the menue. So yeah...to strong for their pricetag
IS: 270
Nades: 100/10
LMGs:150/15 +45m per one
Bolster: 150/35
Realistically add at least 84mp to divide as you won't have bolster before 3rd squad, ever.
Assumptions:
meta 4 squads, unrealistic assumption that all IS start at 5 man and you don't need that extra 28mp for at the very least 3 squads
That means:
370mp +90 muni +15fu investment on per squad basis with meta 4 squads of IS.
Realistically add at least 20 muni per squad for mekits or pyrotechnics.
Obers are 340 + how much was LMG? 80 or 60?
Teching is a matter of timing of the unit, not its actual cost, so stop running face first against that wall, you aren't going to break it.
In no world upgraded IS are cheaper then obers and mathematically, you're as wrong as it can humanely get.