to (one's) cost(redirected from to my cost)
to (one's) cost
To one's detriment; due to one's personal experience with something negative. Unfortunately, he's not as forgiving as we all had thought, as I found out to my cost.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
to your ˈcost(know, discover, etc. something) because of something unpleasant that has happened to you: Joanne’s not a very reliable person, as I’ve recently discovered to my cost.
Farlex Partner Idioms Dictionary © Farlex 2017