I think letting Lehman go as part of a Grand Master Plan assigns too much credit. If they let it go for any ulterior motive, it was political. That way, Bernanke and Paulson could say later to the Congress Monkeys, "No WILL for a Lehman bailout, huh? Well, we TOLD you that was a bad idea, Next time, you will listen to us and let us manage the crisis."
I honestly think that's how Hank and Ben got so much unlimited power so quickly. It was to short-circuit the politcal interference, checks and balances, that sort of thing.
Suckering people into treasuries became inevitable when they kept trashing gold. See, no safe haven here! Please move along and buy some treasuries. People see gold as unsafe because of the volatility. And, anyone on leverage gets killed.
I don't think anyone expected shortages of physical metal to push up premiums. At least I did not.