The margins are pretty low, and with good reason, there's stiff competition. Nothing brings down prices like multiple competing companies, very few possible feature differences and limited overall UI possibility. On tech devices there are really only 3 points of competition: features, ease of use, and price. The way the all-in-one/ uber-cellphone market has shaken out there's almost no competition in features (every device can do pretty much everything, with a few notable exceptions), all the UIs are kind of clunky so there's not much competition there, that leaves price. Apple's habit of sleak interfaces could mean they open up a new avenue of competition, but given how high they're pricing the iPhone I don't think they can win on that alone.
I understand margins are low in the cell phone industry in general. My point is that if Apple is charging over double what other equivalent devices cost, and still doesn't have any higher margin, they've got a big problem.