I don't think I'm going to offer to pay to repair my friend's phone. I'm the one that bumped it out of her hand, but it was an accident.
Why do you not want to pay for the phone repair?
My friend is making me feel bad, she has ruined my sleep for few weeks.
It sounds like this person will be let down if you can't help them. It is bad to let others down. Someday you will need them to be there for you.
I don't think it's fair that I should have to pay to replace it. That's a lot of money.
You should offer to help your friend pay for the phone repairs, especially since it was your fault. It's also not fair for your friend to have to pay for the whole repairs when she didn't do the damage. Support your friend when she needs your help, and she'll have your back in the future.