Dodgers, Rangers, Astros, Braves, Dodgers, Nationals, Red Sox, Astros, Cubs, Royals, Giants, Red Sox, Giants, Cardinals, Giants, Yankees, Phillies, Red Sox, Cardinals, White Sox, Red Sox, Marlins. Those are the last 23 WS winners. Every one of them spent in the top half of the league when they won and I would guess that's the case going back at least into the 1980s.
I don't understand the 'how they were built argument'. Sure, some of those teams had lots of home grown talent, but what does that matter? Every one of them were top half of the league in spending, without exception. If you won't/can't/don't spend in the upper half, you're not winning a championship.