I’m a self-described rookie; I was relying on the analysis in the link I posted. In that specific case, the simulator was able to win with an engine strategy 75%-90% of the time, depending on some issues discussed in the text, and a human is expected to be able to do better…but that analysis was based on a fixed draw (the suggested “first game.”) So I’m sure you’re closer to the essence of it than I was.
The strategy wiki has a good description of Big Money’s place in the strategic pantheon:
Chapel’s cost isn’t balanced to make it fair compared to the other cards, it is balanced so that all players get equal access to the super powerful card
If chapel had a cost of 5, people who draw a 3-4 split couldn’t get one. If it cost 3 or 4, someone with a 3-4 split could buy chapel silver, while 5-2s would likely go chapel nothing. At 2, 5-2 splits have an advantage, but not as much as other potential costs. Whether it is worthwhile or fair at 6 is an interesting question.