I dont know how limited the stock is but I bought one of these for my daughter this morning.
Go to tesco direct (Not the clearance section this is not included in it for some reason) search pay as you go mobile phones and then sort lowest price first and this comes up.
Dont worry if it looks like you have to pay £5 for the delivery becuase they take this off on the payment screen.
It looks like they have made a mistake in the page as it states normal price £44.97 with £10 off now £34.97. BUT the red price is £10 and when you go through to checkout that is what I was charged! I didn't even have to pay for delivery!
A smart phone for £10 delivered bargain!