Are there any guys who know cars well? After I bought it, please

I crashed my parked BMW X4 and I’m thinking of paying for it for cash. The other car owner said he would first go to an official BMW repair shop and get an inspection and charge the inspection fee and replacement fee, but if it turns out to be more than I expected, can I file a claim at that time…?? Ha… if there is an estimate, how much will it cost…ㅠㅜ