TUAW has posted a very interesting article entitled, "Why you shouldn't buy the iPhone 3G on Friday"
Now it's time for the iPhone 3G to appear and by every stretch of the imagination, it's horribly priced--as is every other subsidized smart-phone out there. Unless you live in the Netherlands, the rate plans range from bad to unspeakable. If you're in Scandinavia or New Zealand, our hearts go out to you.
From a price perspective, the cheapest way to use the phone is to buy it outright, unlock it and use it with inexpensive calling plans.