Most of the world uses fixed fee pricing for B2B transactions. The road in front of your house was built by a contractor offering up a fixed price bid. Why, 30 years after the invention of the web, why are agencies still charging on a time & materials basis? Anshey Bhatia's viral post on this subject (https://www.linkedin.com/posts/ansheybhatia_ecommerce-shopifyplus-digitalagency-activity-7355937751537471489-KAE6?utm_source=social_share_send&utm_medium=member_desktop_web&rcm=ACoAAABIk90BajMmOMdE1FcLgzdxuG_mXl3CM0Q) explains the problem with time & materials, explains why it's still (unfortunately) the default, and offers up an alternative.