There is no other alternative to Iphone, u have just 3 models, Iphone, Iphone 3g, Iphone 3GS. Ofcource u can buy other models but then U wont get Iphone OS. I think the price of a Iphone 3G New Sealed is about 30.000 maybe. Im not sure. Someone has to confirm that.
I have never used Iphone but I have used all models of Ipod Touch, both 1G and 3G. They are basically the same thing except Iphone has GPS, and sim support. Im very happy with the use of those products. Qucik, Clean, and Easy 2 use.