Silksong is famously stingy when it comes to its chief currency, especially in the first third of the game. After about five hours you'll probably find that you don't have enough money to unlock fast travel points and benches, let alone buy all of Shakra's maps, let alone buy that Simple Key back at Bone Bottom. I found myself in that situation by the time I hit Greymoor, but after a while I realised there's a brilliantly lucrative farming spot just nearby that you can exploit endlessly.
Not only that but I'm pretty sure this was designed to be a farming spot, because there's a bench within 10 seconds of a mob of zealots who drop around 29 rosaries per run. That means you're looking at around 60 rosaries per minute, or around 300 per five minutes.
