Schu-mines and Soviet TM-35 mines are the same mine. 200 damage, 5 AoE radius, same price. Good mine.
Mines are really good but put some thought into what you really want to use them for. A 30 munitions mine that kills 2-3 Grenadiers or Riflemen is decent value but that more or less equals a good grenade. Some factions/commanders have access to demo-charges which, while more expensive, are far better for wiping out entire squads and will give you a better return for investment against infantry. If you want an anti-infantry trap as Soviets then consider the demo-charge.
Think about your strategy. Are you trying to stall for heavy armor and fear a light or medium armor piece ruining your day? Throw mines on flanks, near AT guns, and generally just behind your battle-lines so that they don't get detonated by enemy infantry as often. Try to preserve them for the light armor that threatens to punish you.
It's interesting to see the rise of Close Air Support doctrine because it really shows how powerful the Wehrmacht teller mine is. At 500 damage it will instantly kill any American tank/vehicle that is not a Sherman. Even the Jackson dies in one teller mine. 50 munitions for 350m/125f? That's value! This little killer is much underestimated.
Actually the teller mine does 400 damage since 1 or 2 patches and cost was lowered to 50
Why does close air support show off tellar mines?
I think, for Werh, if your going to play combined arms defensive play rather than gren spam, S mines are essential as a close part of your force to close some of the flanking routes to your MGs.
They can also really help hold your cut off or fuel, helping your force to stay compact and not get spread out too much.
If you rely purely on paks and optionally a shreck you're very vulnerable to armour charging through your lines. Teller mines deal heavy damage so the flanking tank will die fast.
Provided the teller doesn't bug out like it sometimes does