Need a advice, full cascade loss of opinion diversity…

hello first of all, I have a golf 4 variable 1,9 tdi with 74 kw ez. aug.2004 with 51120 km… now I have a damage on the car and that is the whole right side…. to repair the bumper, to renew the door, to repair the rear door, to repair the side part and to repair the rear bumper… now I was with the car at vw and asked for a cost estimate, there they told me the damage was 4900,-euro and I should have an expert come….. .he then also came from the insurance and made an opinion, where then the damage to 2877,85,- is estimated……that’s 2000,- euro difference……that’s why I went to the dekra with us, they looked at the car and arrived at a amount of 5113,- euro…. what can I do now???? for 2877,85,- get the car nowhere repaired….except in the backyard manyths. can I somehow deal with it,if how???? help me…..be grateful about every advice mfg nicole