I have sat in on some of those. It is still hard to understand the true market based on those live sales, there are certainly some ego purchases as well as some people racing to grab the book before the seller really gives a grade or description. I recall one with a lot of good Silver Age that when the books were quoted as VF- and VF+, the Host and others would ask, "what is the number grade" once they said "8.5" 4-5 people try to buy it. I felt like in that one I only got lucky buying books prior to the host asking for the number. I can't say I have seen something we would consider a key go for a deal in the live sales. The Hosts do a good job of helping hype up the books ( "guys this is a newsstand" and boom gone) to create that FOMO as you mentioned. I have started to see as others have mentioned books sit now though on their feeds and some during the live sales.
I bought a couple of bigger books this year that were books I had hoped to get last year, they felt like they had (Hulk 1) some increases due to the timing but if they fit what I wanted they came home. What I personally have done is go back into runs and other books I have overlooked like TTA in grade in the past and had decent luck on those. Those are still off the radar for the most part. I had a few DC SA keys I had planned on getting but they just are not coming to market so no sample size there to share.