Yep, GPA only has 2 sales for CGC 9.8 Bone #1.
$4,750 in December 2016 and $3,216 in 2008. Owners of that book don't seem willing to sell.
It is definitely one of those books that tends to stay in collections. I do know of a few private sales and the $4750 is also higher than any private sale I'm aware of.
It's also an incredibly difficult series to complete a 9.8 set of. Even if any one happens to see any solid 9.8 candidates of the later issues in the wild they are worth picking up, I know I'd personally love to see some later issue 9.8's hit the market for my run.