I'm sure negotiating becomes easier when you don't need the money. It's not dissimilar to playing poker with a sufficient bankroll to withstand the swings.
That is obviously the case. But there are several ways to playing winning poker, as with making money with domains. Imagine the offers he keeps turning down for alot of his names, offers 99% of us would have accepted. Obviously he will win a few big pots, when that is all he is trying to do, but there is nothing wrong with chipping away and picking up the small ones. In fact, that is a very common trait amongst pokes pros, perhaps even more so than amongst newer players
To continue with the poker analogy, Frank seems keen to maintain his "table image", and for good reasons. I am not claiming he is doing anything wrong, in fact, from what I have seen/heard of him, he impresses me alot.
On a side note, I have an eye on one of his top .com's. I am currently developing the name in other TLDs, and if it turns out to be working, I plan to contact frank for a joint venture . One must be allowed to dream...