It’s not easy to build a Major League Baseball team. Well, it’s not easy to build a good Major League Baseball team. It used to be that you could be the New York Yankees, throw a couple hundred million dollars at free agents, and be a perennial contender. Thankfully, it’s not that simple any more.
Nowadays, if you want to compete, it has to start with development. Teams (for the most part) aren’t stupid anymore. Few teams will get fleeced in a trade, few bargain-bin free agents are to be found, and the market inefficiencies of yesteryear have all dried up.