I think we will see discounts before too much longer for the Andrew run -- typical Broadway thinking tends to be that if you're going to need to discount, you should be out there with an offer at least four weeks out. With NPH, in the months prior to first preview, it was just a handful of select dates (maybe a dozen each time?) and the discounts were only in the mezzanine and balcony as I recall. This time around, I wouldn't be surprised to see more expanded availability, but they're likely never going to offer their best seats at a discount. The airlines don't do it with first class seats and theatres don't seem to do it with their prime inventory either. As it is, though, the producers would appear to understand that Rannells does not create the same demand as NPH. Look at the premium prices as of 8/20. They're back down in the $200-$250 range. And regular full price seats are back to their February levels in the #140 range for top price. So as others have already noted, what they're doing with this last month of NPH is simple supply and demand. When there isn't the same demand, the producers seem to recognize they can't mark up the supply nearly as drastically.
As for me, I'm definitely going back and hoping that I'm right about the timing of the discounts. I don't have the flexibility of doing the lottery or standing room so I've paid a lot of money twice to see the show already. I'll be delighted if the third time, I can perhaps lighten the impact on the pocketbook just a smidge!
"No matter how much you want the part, never let 'em see you sweat." -- Old Dry Idea commercial