No idea where you'd get a new first generation iphone.
i got mine frm a firend who bought frm UK .. so no chance of gettin again ..
You should still try getting it from O2, the iphone 3g that is. Will be cheaper and you'll also have a warranty (obviously only for the UK but a warranty nonetheless).
The iphone is expensive anywhere in the world but in Pakistan the price is just ridiculous.
You don't need a turbo sim now either. (iphone dev team zindabad!)