The cost of entry to the Apple App Store might be dropping to zilch soon, says RBC Capital Markets. G.M. Mike Abramsky sent a note to investors that the retail price of the iPhone 3GS is expected to drop to zilch when the next-gen handset releases.

Here’s the thinking behind this: The freebie iOS offering (with a 2-year contract, of course) would be an aggressive defense strategy to stave off competition from mid-tier smartphones, as well as Android devices. By emptying its closet of these handsets, Apple could more than double its current global iPhone userbase from 64 million to 150 million worldwide. This would be huge for Cupertino, particularly in regions outside North America.

Inside the U.S., however, this could be a worst-case scenario for at least one (possibly two) carriers. There is no CDMA iPhone 3GS that Verizon could even offer, so where would that leave Big Red? And what about AT&T? The GSM carrier infamously buckled under the weight of iPhone users for years. If it starts offering iPhone 3GSes en masse, would the influx of data exacerbate data chokeholds (again)?

Yeah, I know — there are some among you who wouldn’t take one, even if it was free. But anti-Cupertino cracks aside, let me ask: Is anyone else dreading this possibility? I’ve never been one to reject the idea of budget-friendly options for the masses, and I could see a lot of people benefiting from this, but it seems like giving out 3GSes could cause real chaos, no? Let me know what you think in the comments.

[via BoyGenius Report]