I use the Blue Book too, to get an idea of what a particular firearm is worth on the average market, It may or may not be "right on" all the time.
I'm sure most of us, or at least I have often paid a little more than I wanted to at times, just because I had to have it, and had no idea when another one may turn up. That's just my nature.
Like you, I keep updating my collection value and my insurance premium based on the Blue Book values. It's what I generally refer to when someone on here is looking for an approximate worth on a gun.
Also, what is hot and commanding top dollar in one place may not be much of a mover in another part of the country. I love it...........