Well... You will be very lucky if someone calls you to sell an iPhone for 800-1000 riyals. I am talking about the iPhone, which was released last year (NOT THE 3G). Even an upgrade of the version would cost you like 100-150 riyals (if you dont know how to upgrade or jailbreak).

My guess is that a used iPhone would cost you like 1800-2200 riyals.