When a job is too expensive for someone, the instinct is to knock money off. That teaches the customer your first number was invented, and it teaches you to resent the work.
Set a minimum you will not go under. Then build a genuinely smaller offering that lives at that number — fewer revisions, a shorter session, a tighter scope, standard rather than custom.
A four-hundred-dollar job that was designed to cost four hundred dollars is profitable. A nine-hundred-dollar job you talked yourself down to four hundred is a nine-hundred-dollar job you are now doing badly.