I had a similar situation come up recently with an air conditioner installer who was working at my house and had a chip he wanted to sell.

I showed him the chip (shown below) in two different guides, which showed a price ranging up to several hundred dollars. He asked me what I'd give for it and I told him I wouldn't be willing to pay more than $100, simply because I don't normally pay that much for my chips. I even offered to help find a buyer for him through my contacts.

Much to my surprise he said he would sell it to me for $100, which I forked over quickly before he could change his mind.