Dented my bumper and nearside rear corner and decided to get it all done myself. Just didn't want to involve the insurance
company. Like you I knew they would write it off. My wife had somebody wipe the side of their car across her front wing, not a lot of damage to the Discovery 1, just needed unbolting and the new panel bolted back on and a bit of paint. The other cars insurers tried to write the disco off until I told them politely?? on the phone that it's BL**** stupid to write of a Land Rover as plenty of parts available.
Another point, If the insurance company get involved, they have to report the incident, no matter how small, to some central system and this usually means that your next insurance will be higher as you are now listed as a higher risk even thou it's wasn't your fault. Have you asked the other driver if they would pay towards it, it will put his insurance up as well.
If you sort it yourself and they do hear about it, say the repair is just cosmetic.
A before and after of my car.(it was done in a local bodyshop not by me) I got the lights of Ebay and the bumper of
a Forum member for £70
https://www.dropbox.com/s/al586r212uraxa7/2014-06-24%2017.06.04.jpg?dl=0https://www.dropbox.com/s/y7jm049gneh7uz9/2014-10-20%2015.22.24-1.jpg?dl=0My sons truck behind was what I hit, It's not usually in the yard, was that day!!! who's a silly twit.
The real value of your car is what it is worth to you.