In general, most providers have a lot of fine-print. We tried to come up the simplest and fairest pricing we could.
ACH is a heavily commoditized product. For ACH processors, then, your business model is tied to the functionality and capabilities offered by the platform. Dwolla, which has spent the last 4 years exclusively building out its ACH API, has a range of free and paid-for products and services. This allows us to offer a fixed flat-fee price point based on the additional value we bring to platforms (instant account verification, next-day processing, higher limits, holding balances, etc.).
Both services do an excellent job at baking in the expensive compliance, support, regulatory, etc. into their products.