28 pierce would be way too much.
I started with military pick, and gave up 2 speed, 2 dmg, and 1 reach (5 total stats) for shieldbreaking.
Grosse Messer gives up 3 speed, 1 dmg, 1 reach (5 total stats) for shieldbreaking (i.e. fighting axe).
I consider the thrust on Grosse to be equivalent to the secondary mode for fighting axe, so they cancel out.
6k, 8k, whatever. No one really cares about 1h weapon cost, there was no logic behind my 6k proposition.