My guess is that it will be worth a lot more initially because of the apparently low supply compared to demand. By the time it gets jailbroken, supply would have caught up and it won't fetch as much. Plus, who knows if it'll get unlocked in a timely manner either. AFAIK the latest baseband on the current iphones STILL hasn't been unlocked, and hasn't been for a while.
Long story short: sell ASAP
You are misinterpreting this. Yes the latest baseband has been hacked, the dev-team just didn't release it. Why release the new baseband hack 2 months before the new phone comes out giving Apple the leg up?
Instead, you don't tell anybody that its hacked and hope when Apple releases the new phone the baseband is similar enough that the dev-team can get it hacked using the techniques they learned on the latest baseband which Apple thinks we still haven't figured out.
I can promise you, I don't know the dev-team personally, but I know devs in the scene and they've had their ear to the ground. This is the scenerio they've told me has been played out in the last 2 months. The dev-team isn't saying anything about anything, and rightfully so - they don't want their hard work to be in vain.
Now, we still don't know how much the baseband will be changed on the new phone. But the few I've talked to seem to think Apple will not change the BB on the new phone that much because they think they are that one step ahead right now. But, then again Apple knows this is a cat and mouse game - they might step it up yet again and the dev-teams efforts will have been in vain.
However, 3Gs owners with the latest baseband will be able to unlock within a few days of the new iPhone release, for sure. Quote me on that. And as I said above, the Jailbreak will also be in affect for the iPhone 4 most likely very soon after release. They have already jailbroken iOS4 for sure - and it might need a few tweaks for the new phone - but it will be a matter of days. Again, quote me on it and call me out if I'm wrong on either of these 2 things. I can't say for sure on the the unlock for the new iPhone4 but most in the scene have a feeling it will be a matter of days as well.