Not sure of what does "ready to unlock" means. I hope the contract on the device is finished and it may be ready to unlock. If the device is available for a good deal, You can get it and unlock it yourself.
You can unlock an iPhone safer and easier using remote unlocking service. You can get the remote unlocking service for an iPhone from Simpleunlocking.com at affordable cost with easy unlocking guide. This is a permanent unlocking method and doesn't require a jailbreak too. Good luck mate.