[Blueface]

Peter, not a buy back.
What you are looking to do is retain salvage.
Most if not all states allow that.
Depending on insurance company, they may try to fight it.

Basically, they determine ACV (actual cash value), plus applicable taxes and DMV fees, and deduct a salvage amount which they generally get from calling three salvage yards for bids.

You can certainly find a shop willing to repair quarter panel and that alone will be a significant savings.
Next, don't blend. Live with any possible tint and blend mismatch. Paint and materials adds serious bucks.

Good luck and let me know if you need help along the way in the total loss process.