Mike Sterling asks about predictions for the price of floppy comics from the big-2. He notes that we're already starting to see $3.99 per issue mini-series; often these are for 40-page comics, but sometimes (especially with Marvel's MAX titles) it's a regular 32-page comic with cardboard covers.
Right now your standard big-2 comic is 32 pages--21 or 22 pages of story and ten or eleven pages of ads--for $3, and as Mike notes they've been that was for a long time. Something has got to give, and probably soon.
I can't see just raising the price to $3.50 as working. While enough people are willing to shell out $4 for an IDW or Boom! comic to keep those outfits running, those books also have no ads interrupting the story (just house ads in the back of the book). I think there's a psychological barrier for the $3 price point that your average super-hero fan just isn't going to cross for a 32-page book.
Increasing ad space won't cut it either. Marvel has tried adding 8 extra pages of ads to a comic, to universal disdain. (DC has had ad inserts in the recent past too). When the amount of advertising reaches par with the number of story pages, consumers start to wonder why they're shelling out $3 for something that is mostly ads.
So I only see one way they can go: increase the price while also increasing story content. $3.50 for 27 pages of story (and 5 pages of ads) would work well, but more likely it will be $3.99 for 29 pages of story and 11 pages of ads.
Another option is to use lesser-quality paper; DC does this to keep the price of their Johnny DC titles down at $2.25, but in general consumers have shown a preference for the shiny paper stock and fancy computer coloring.
Ultimately I'd rather see 100-200 page anthologies (i.e. the 'manga model'), but getting to that point from the current model doesn't seem likely to happen. However, the industry does seem to be making a long transition to a trade collection model, and as that becomes more and more prevalent perhaps the large anthology-as-loss-leader model will become more attractive.