bargain for something ( also bargain on something ) phrasal verb ( see also ↑ bargain )
[usually in negatives] to expect that something will happen and make it part of your plans:
They hadn’t bargained for such a dramatic change in the weather.
bargain on doing something
I hadn’t bargained on being stuck in traffic on the way home.
The thief got more than he bargained for, as Mr Cox tripped him up with his walking stick.