DavidS knows chips very well. You can be sure that any chips that were in reasonable condition are not in the junk lot being sold on eBay. There have been a number of $5 HNO chips surface in the last year or so. The next revision of either chip guide will reflect the drop in scarcity. Also, remember value is determined by both scarcity and condition. IMO, if you have a nice chip, its value won't be affected much by the availability of buried chips with warps and water damage.