Picking up the Nokia Asha 503 SIM-free will set you back about £100. However if you sign up to a pay-as-you-go deal, you should be able to get the 503 for under £80 - an absolute bargain.What the Asha 503 lacks in screen size is made up for with solid battery life and it offers most of the features you’d expect from a modern smartphone. Running on Nokia’s Asha software platform 1.2, the 503 is smooth to operate without much lag. The operating system is very basic, but that does mean it’s easy to use.