My guess that it will sell at $4250
$4350.
There may be a ceiling for restored or even slightly brittle copies, but it seems like there's also something of a floor. I'd guess that "most times" a #35 with a cover that presents that well is going to break $4K, almost regardless of its other qualities.
I agree with both of your range of estimates.
And P5, I completely agree with your reasoning of Tec 35. As I said earlier I believed (and still pretty much do) that the general going rate of a Tec 35 with a cover regardless, should be more in line with 5K. These EP are just odd balls right now and the fact that there are too so close probably hurt the rate of the former.
I think your dead on with the floor being 4K, and frankly due to the volatile nature of the book, even though sources indicate the 3.0 EP should logically sell for much lower (say a grand or so) than the 5.5 EP, I still would not be surprised (however unlikely) if the 3.0 EP somehow sold for more than the 5.5 EP - given how volatile the market is. And as Rick said that 5.5 had a poor visual appearance in person.
It's already sitting at $3,101 with 12 days left.