The fact that someone is coming to you specifically to find out the value of the chip differs from someone offering it to you for a very low value, in my opinion. People are free to set a sales figure. In that instance, I can understand someone buying any collectible at a very low price, even knowing that the "value" is much higher. However, this person is putting his trust in you to give him an honest appraisal. I can't see justifying a false answer in order to get a bargain. I agree with Jim that you should share the real book values, explain that he may not be able to get that amount, that it was the retail value at the time the book was written and that values can shift over time. Then, you are free to make whatever offer you can. If the chip is out of your range, at least you will feel good about helping someone.
If you get the chip, you can feel great about it.
Ultimately, only you can determine what you should do. It's just my opinion.
Michael Siskin