DC's prices have gone up to 4 dollars

If they hadn't done so before, they have this year, with several titles that are now a solid $3.99, more so than before, no doubt part of the publisher's idea for how to "compete" with Marvel. This includes Superman Unchained, and you can be sure not many people who've seen the Man of Steel movie will be encouraged by that.

They might lead to sales going up short-term, but long-term, it's bound to discourage more loss of readership for pamphlets.

And, if I noticed correctly, even some independent publishers have been raising their prices that much for monthly pamphlets, which really isn't wise if they ever wish to make it big even with people new to the medium. But I guess they don't. That's why there's such an insufficient effort to advertise comics outside their own press.