Simple reason why the Turbo Buicks bring so much $$$ is that they’re the only Gbodies that came with balls like the 60s-early 70s cars. That’s why the rest of our loved Gbodies will be looked down on. I personally LOVED that the CBB Elco sold for $6,000.00 more than the pristine original H/O
https://www.mecum.com/lots/FA0820-442053/1987-oldsmobile-442/
$32K (double Sticker) for a 10K mile '87 442 is pretty strong money. Even if there wasn't two bidders that absolutely had to have it, it would have been over $20K.
There were Millions of G-bodies built so lots of people liked them. Desirable ones in excellent condition should bring good money. One of the things that triggered the rise in GN values was they went emission's exempt in Rolling 25 year states, like Texas. My $12K GN sold for $22K with the help of that one little change. Now being let in to Good Guy's events won't hurt, either.