I regard 'the hunt' as having great intrinsic value; but the context must be right. Rare stamps are just that; rare. And when I find something I always try to remember that extra-ordinary things require extra-ordinary proof. This means I do not trust myself on subtle color shades or difficult watermark calls.
I usually ask meekly in this forum for opinions knowing that the most definitive approach is to send the stamp in for a 3rd part opinion in the form of a cert. For example see this thread
https://goscf.com/t/36715&SearchTerms=423bBut please note that while we all aspire for these kinds of finds, they only come around rarely. The find like the 423b has only happened to me 2-3 times and I have been collecting since the 1970s.
So have fun and relish 'the hunt', but keep your expectations in check.
Don