A lot of people don't know what stamps are worth, or catalogued at, or sell for in different markets at different places at different times. Why would they? No way can they tell. It's not in the daily paper or on the TV or Radio every day.
Heck, I don't know a lot of prices and value info. I can see a nicely centered well preserved item might be worth more than one not so, but then we get some stamps that look pretty beat up and they are still worth something. It can be confusing.
It's not just old stamps that are worth something. New stuff can be also, if sold correctly and to the right market of course. I bought a 2010 Canada booklet of stamps for $5 roughly and after research (helped by many of here, thank you) sold some for over $100 or $200.
It's the learning of what will be collectible and worthwhile and fascinating to a stamp collector that makes this hobby fun in some ways. Not all of course. I like sorting and soaking kiloware and seeing brand new mint stamps in all there glory and the postal history covers and information.
So, to have these skills that allpw you to recognize what is valuable and worthwhile in the stamp world is something that only comes after years of playing around with stamps. It is unreasonable to expect a newcomer or a newbie or a beginner to know this stuff. The poor helpless things are taken advantage of enough by the sharks and wolves and predators out there.
Your job, should you choose to accept it, is to teach these poor, helpless newcomers what you know, in a way they will understand hopefully. There is, of course, the responsibility on the newcomer himself to want to learn and to apply himself to learn what he can.
Everybody has their own level of skill at learning or at different aspects of our hobby. Of course you can learn more, if you want to, and I think wanting to do something goes along with seeing some value or worth in it, and as mentioned above, sometimes value and worth are automatically equated with money, and this is encouraged by some dealers over the years.
One of my nephews, bless his soul, when I told him I was collecting stamps and also buying and selling on
ebay, asked me, first question, do you make any money? I was a bit startled by the question,a s a stamp collector would not ask such a thing in the usual course of events. He isn't a stamp collector (yet, still working on that), so I had to readjust my thinking around to how he thought. Funny in a way it was.