WANTED looking for an iphone 4 or 4s cash waiting +

Looking for an Iphone 4 or 4s in good condition ASAP Must be either unlocked or on 3 network. not fussed about colour or size of memory but must be fully working and in decent condition, preferably with box and all accessories and preferably with a receipt or some sort of proof of purchase as i have bought one before which a week later was either reported stolen or contract was bumped and the phone was blocked. will pay up to 300 for right phone can collect cheers