"Bigger" in what capacity? More content? More explorable landmass? More quality(TM) explorable landmass? Longer playtime? Longer playtime of quality(TM) content? Etc. I think you're getting my point. Lots of sources for contention with an "objectively" correct answer being very improbable.
Having played (and still not nearly finished WL2) I'd say that has a lot of landmass to explore. I'd be surpized if PE has as much. (Simply going by comments from Sensuki a few months back, which suggested that PE would not exactly be fuckhuge. [EDIT] Sawyer disagrees. LOL [/EDIT]) On the other hand I'd expect PE to have less empty areas/more content...
*shrug*
I also don't think, that it's a good means to measure cost of 3d vs 2d. Since the game budgets might have been similar, but that doesn't mean that the graffix budgets were similar. Unless some employees from both studios would like to enlighten us
Anyway, given the release discussions:
Anybody else planning on leaving PE alone for a weak or two after release? Just to wait out the inevitable hot-fixes/patches. (I don't expect that I'll manage to actually resist the draw. But until I give in, it'll stay my plan.)