In order to trade for one of the Lineage's legacies, Sylas needed 100,000 points. And these were just the lesser Lineages. If he wanted one of the top four—the Whale, the Serpent, the Ape, or the Lion—it would cost anywhere from one million to over four million.
These prices were practically arbitrary, and looking at them now, Sylas could tell that they were set based on the whims of the Warlords.
The cheapest was actually the one he wanted, the Whale Lineage, at "just" a million. The most expensive was the Lion at 4,500,000 War Points, and the second most expensive was the Serpent at 3,000,000 War Points.
You could practically scale all of this based on which Warlord hated him the most. He had no conflicts with the 713th Whale Warlord, but he had defeated the number one E-tier Serpent Lineage disciple, and he knew that his thwarting of the Bat Lineage had ruined the Lion Lineage's hopes for supremacy.