You mean like FF 110? Very good question. I'd've thought such an error (I've not seen one of those before, fwiw) would've been treated the same way. There are no structural problems to qualify the grade.
I assume it could go for more than a regular Avengers 10 as it is rare - but the market is sometimes skewed regarding error books like this. FF 110 "green" version usually goes for a large premium, especially in high grade, whereas other books with similar "defects" do not. Maybe it's because it's still aesthetically eye-catching, but that's just a guess.
Either way, great books - impressive how many have white pages. And that Cap 110 is the nicest (whitest) I've seen.