I don't think you can say that in general price guide values are too high. They are dealer retail prices. If you check the Convention bourse this month in Las Vegas, I suspect the kind of chips you mention will be listed generally at price-guide levels. That's not to say there won't be some discounting to buyers of multiple chips... there usually is. And yes, some individual chips are overpriced in the guidebooks; and some are underpriced in my opinion.

Also remember, that even though eBay gets a lot of visibility, not every buyer of $200+ chips checks the listings every week. I've found that in the past when I was selling more on eBay, it helped to advertise the auctions here on The Chip Board with PICTURE OF THE CHIPS IN THE AUCTIONS! Just a couple of opinions in response to your post.