I agree that the completed auctions on GB are a good resource, and using it wisely will allow a SALE.
As for the Blue Book,, several of us contribute to the RENE Price Guide for Rugers. That information is shared with every years publication of the Blue Book.
THE RENE PRICE GUIDE IS FOR BASED UPON WHAT ONE COLLECTOR WILL PAY ANOTHER COLLECTOR FOR SPECIFIC GUNS. CONDITION IS TAKEN INTO ACCOUNT, AS ARE THE ACCESSORIES SUCH AS THE BOX(S) & PAPERS.
We do this annually, and try to be realistic in real world SALES,,,, not,, I repeat NOT what we'd like to sell our guns for. And CONDITION is also described in our Price Guide. Sadly,,, too many people think their gun is in better condition than it will actually grade out to be. They see the 100% condition number,, and think their gun is 98% or so,, while it'd actually grade at 90% MAYBE. Condition means a LOT.