$125 is outrageous. My guess is that they just don't want to transport the bikes so they charge a high price to transport them hoping people will rent instead of bring. Well guess what, they are going elsewhere as you did.
It would be one thing if $125 guaranteed delivery free of damage but as many of the posts here have written, the airlines want to wash their hands of any damage or lose.
If we had as many company executives that rode instead of golfed, then bicycles would be free on all airlines.