I've seen this dismissive logic before. However, in point of fact, reputable price guides are not worthless, especially to the amateur. They are guides, not gospel. For those of us who pay little attention to, say, Post War items, but appreciate them on occasion, a price guide helps us understand the difference between a $40 item and a $400 item. It gives the uninformed occasional buyer a starting point.
For you experts they probably are not very relevant, and everybody understands (one more time...) that a thing is only worth what the buyer is willing to pay - but that has little to do with being "guided" into the general ballpark.
Guides are not "useless". They are tools. Me, I use eBay as my national marketplace price guide. I don't take it as gospel, either.
