You can sign a great player, but that's just about writing a bigger check than anybody else. You can draft a great player, but that's just about your pick coming before somebody else's pick. The true connoisseurs know that the fun is in trades.
In a trade, it isn't enough to spot the talent or have the resources. A trade requires persuasion and sacrifice. It demands that a GM sell somebody on a hypothetical in which this lives there and that goes here. It puts a smart GM in a position to embarrass -- or be embarrassed by -- another smart GM.