First Bank said the legal, investment banking and other costs of the takeover fight were about $10 million.
Analysts estimate that the three companies could collectively spend more than $100 million in the takeover fight.
"It's rare to have religious and charitable groups involved in what is a takeover fight."
Any sign of friendly resolution appeared far off in the two other takeover fights.
The takeover fight led to management actions that made the company stronger, he said.
The letters were another sign of how nasty the takeover fight had become.
In many ways, the takeover fight marks a key test of Germany's openness.
And Kemper stock fell to below where it was before the takeover fight erupted.
The latest battle comes at a critical time in the takeover fight.
Like a patient who needs an emergency operation, a company in a takeover fight cannot concentrate too much on cost.