From Longman Dictionary of Contemporary Englishbargain for something (also bargain on something) phrasal verb[usually in negatives]EXPECT 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. → bargain→ See Verb table
Examples from the Corpus
bargain on doing something• I hadn't bargained on it taking so long.• But he hadn't bargained on Hodgson, who was clearly looking to leave a lasting impression on his future rivals.• That was more than the Corps and the Bureau had bargained on.• We had not bargained on that result, but nations rarely anticipate the consequences of war.• What she didn't bargain on was you whisking her off to the country and locking all the doors. 