In a note to clients, Piper Jaffray analyst Gene Munster comments on Apple. Piper’s channel checks show iPhone demand at AT&T stores is up at a sustained rate of +70% to 100% post-price cut. In a note from earlier this month, Munster had expected demand to stabilize at +50%.

Piper, incorporating in these new checks, suggests Apple will sell 1.05 million iPhone units in the September quarter. PJ’s previous models had suggested 1.01 million phones in the quarter.

In the note, the analyst explains that while 40,000 additional iPhones may seem irrelevant, investors should be mindful that this increase is the result of just 21 days of the quarter at the new US$399 iPhone price point. If one assumes that this +70% run rate is sustainable, which it seems to be currently, it would add approximately 170,000 iPhones units to a full quarter.

As the holiday gift-giving season looms.

Piper Jaffray maintains and “Outperform” rating on Apple with a price target of $211.

[Attribution, Notable Calls.]