Most of the time, your $ either need to come from stop cards, or for the cantrip $ (Market/&c.) you need to buy a lot of engine components on top of your +cards/+actions, because they cost ~$5 and add ~$1 to your total spending power. (Conspirator and Peddler are notable exceptions). Bazaar costs $5 and doesn't let you save money between turns, and Fishing Village only draws half a card, so you're more likely to get it without the +cards.
In a Plaza deck you only need to keep a few Treasures around, which you already had anyway, and then your village also provides economy. That means fewer components to add after your draw engine is built.