How much does it cost to repair a car scratch?

Ok, so this is a really weird question to post on here lol, but I’m hoping someone may be able to help. I was in the garage parking my sisters car. The garage in my building is very narrow, with a lot of cars. I moved forward so that I could backup into the parking spot, but when I went in reverse I realized I tapped the car that was parked in front of me. I didn’t even feel myself hitting it. My sister is upset (which she has every right to be), I said I will pay for everything. She says its going to cost over $2000 to get the persons car repaired. I’ve never had this happen before so idk what it costs. Can you give me an estimate on what damage like this would cost. I will post pictures below. The car showing the lights is my sister’s car.