the people, at the first book for the most part,are not necessarily there to.. they aren't there necessarily on the quest for the best bang for their buck. they are there to be seen, they want to be associated with the best just as much as they want to win. they don't want to just win they want to win big races. they not only want to win big races, they want to do it with the best / most established bloodlines they can. Because there is a small handful of horses that makes all this possible, you get fireworks. fireworks drive up price.
Look at it this way: the people who are fishing in the Book 1 pool are not there to buy racehorses. They're speculating on the value of future breeding stock.
Look at Fusaichi Pegasus. He was by Mr Prospector out of a Danzig mare from a high class family--breeding was perfect, if he would run. And run he did. That $4 million that was paid out for him as a yearling suddenly seemed like a bargain compared to the $60 million Coolmore paid for him in syndication--15 times his purchase price PLUS his substantial winnings on the track. At stud, Coolmore priced him in such a way that he would pay off that $60 million in his first 3 years. Everything else has been pure profit for the shareholders. Even if he stands at 15,000 a year for the rest of his career, and only covers 90 mares in a year in both hemispheres (probably on the low end), 20 shareholders would make a minimum of $60,000 each accounting for the expenses related to his care.
The same can be said for buying Mariah's Storm and putting her in foal to Storm Cat. Coolmore won BIG on that gamble, even bigger than Fusaichi Pegasus.
The reason those buyers are focusing on those bloodlines is that those bloodlines are the ones where speculation has a snowball's chance of paying off. Nobody is going to pay top dollar for a son of Pleasant Tap, even if he were a full to David Junior, either at the yearling sales or in syndication. Nobody is going to pay high 6 to 7 figures for a daughter of Include, even if she is a Gr-1 winner (Panty Raid, Cash Included). They would for a daughter of Hasili, even if her sire had been a dachshund, because Hasili has shown such an amazing ability to breed the high-dollar, high-stud fee colts.
It's gambling, off the track.