Live rock question

[Toxik]

I was talking to a guy at work today that has had his live rock in a rubbermade container for 6 months. I'm not sure if he has had a heater in the water or done a water change at all. He thinks that all life is gone and is just base rock. I havn't seen it yet but he was saying there are some very nice pieces, big and flat. I was thinking of buing it off him but not sure if it is a good idea. Do you guys have any advise? What would it be worth? I don't want to rip him off nor do I want to be ripped off.
Thanks
Dave