They really aren't. These are auction results and the results of sales direct from dealers in Japan from their websites.These are just examples of hyped up asking prices. I think very few buyers are paying that kind of money. It's difficult to be precise, particularly on 6215's. They so rarely turn up for auction, but I can imagine fine examples easily clearing $10k.Whilst the models listed here are not in my area of expertise, I do see lots of them sell when looking for vintage GS.
Certainly for the divers, I think the figures are significantly below market prices. I've seen multiple 6215's sell for over $10k over the last year, Suwa 6217-8001's for over $5K, a small crown NOS 6217 go for close to $8k, etc etc.
Hodinkee sold an average 6217-8000 for $4,500 recently.
In reality, 6139 Pogues, 6105 and 62mas divers are not rare watches, at any time there are plenty available, often in poor to average condition.
I keep an eye on thousands of auctions, and check 50 or so Japanese dealer sites multiple times a day.
With all due respect, I know what I'm talking about here.