Teller mine = 60 ammo
Soviet mine = 30 ammo
German sniper = 360 mp
Soviet sniper = 360 mp
As for the sniper war, the thing is they're equal only at higher skill level, where the German player can use micro, camo and vet ability to play around the disadvantage; at lower skill levels, it's very easy for the Soviet player to just a-move his sniper and not worry overmuch about it. 221 completely sucking doesn't help either.
Soviet truck: 120mp 30fu.
German truck: 120mp 30fu.
Soviet one dies to 1 mine with 0 chance to survive, german one backs off with engine damage.
This is what you should compare instead of mine costs.
And if they are fine at higher skill level, then they are fine overall. You don't balance competitive RTS around medicore/bad players, you balance the games for high skill games, where balance matters most.
If you are at disadvantage because you're not good enough, then improve yourself.
Soviet sniper is safer ONLY against vet0 german sniper, otherwise its in just as much danger due to better and more accurate german weapons.
Snipers survivability is fine on both sides. Their killing power is also fine on both sides, at far range german sniper shoots twice as fast already after most recent nerf to soviet sniper.