Buying an unlocked pre for ATT.....good idea...?

*I just realized this maybe should be moved to The "Other Carriers" subforum. Sorry about that.

So someone I know is gonna be looking at the pre and the iphone.
This person needs a phone that works internationally, also the ability to swap sims is nice.
They currently use ATT and would like to keep using ATT especially due to rollover and stuff like that.

I really dont' know much about plans and all. But I want to know your opinons on if its crazy to just buy
an unlocked european version(of course when it comes out in a few months i assume).
Of course I am hoping it is coming soon.

I assume it will cost about 550 by itself. If you consider the fact that it costs 200 on sprint,
thats a 350 difference of course.

My question now is, what kind of NET price differences are we talking about if we compare:
1. Pixi on sprint with contract
2. Possible future pre on ATT with contract(when ATT gets the pre or other web os when the exclusivity runs out).
3. An unlocked pre on ATT with a plan that gets it what it needs.(sorry I donno specifics on this)

Would getting an unlocked pre and then using it on ATT end up being a significant larger amount of money spent?
Would that end up being more than getting an Iphone ON Contract?

This person will need 3g data and all but is not a crazy texter or talker.
Is any of this even worth considering?

Thank you for taking the time to read this.

Yes, I think you need to see first when the GSM Pixi's come out.

Sprint and Verizon both use CDMA technology (which basically limits their cellphone use to the US).
GSM is more widely used and would be more useful for international travel.  You can't go between different technologies, but you can switch between carriers that use the same technology.  i.e. you can theoretically switch between Sprint and Verizon with the same phone and also between AT&T and T-Mobile, but not between say sprint and AT&T.

If you or your friend need this phone *right now* then get a 3G iPhone and jailbreak it.
This will also allow you to use foreign SIM cards (i.e. pay as you go or prepaid) to save money too.

As for a cost comparison, I will say this:
If it's on AT&T you can pretty much bet the plan pricing structure between the Pixi and iPhone will be comparable, if not exactly the same.  The only difference would really be the cost of the phone itself.
The only way you *might* save money is if you get a phone without the plan (likely to be hard to do initially for any of these high end phones) and hack it so that you can use T-Mobile's plans and pricing (assuming their network works well enough for you).  Even then it still may not be quite worth the trouble.  Best would be to pick up a USED GSM phone from ebay and then hack it so that it's both UNLOCKED (i.e. can switch carriers at will) and NOT UNDER CONTRACT.

Sprint is CDMA, AT&T is GSM, they RARELY mix.  Also, AT&T's prices are a lot higher than Sprint's.  I pay $30 less on Sprint than my roommate does on AT&T and my plan has more features...

It will most likely come to ATT, unless Apple renews The iphone contract, on the condition that Att dosn't get the pre, or the android. Or something like that.