Depends where you get them.
Yes, well, I wouldn't know because as far as I'm concerned there is very little point indeed in getting your iPhone/iPad via your mobile phone operator unless you enjoy being locked into 24/36 month contracts and simply paying for your iPhone/iPad via amortisation.
There is very little reason not to buy directly from Apple, and indeed, if you see "new" iPhones/iPads at more than 5% less than what Apple charge for them, I would be very suspicious indeed of how kosher they are unless the seller is large,well-known and trustworthy and may well be exercising further economies of scale.