Play is also an anti-competitive monopoly as well. Google was a bit smarter about avoiding potential anti-trust though, because they at least give the illusion of choice with 3rd party app stores.

There basically is not a competitive market for either app marketplace right now, so an accurate price can't be determined. Allow 3rd party marketplaces to be installed as easily as any other app and I'm certain prices will come down from where they are today.