From the information given it sounds more like a classic example of not agreeing a schedule of work and an estimate or quote of the expected price before the work commenced
Doc H.
Hit, nail and head spring to mind.
many people have said to me over the years, don’t worry about an estimate .... to which I ignore and send one over ..... with clear deliverables and more than once I’ve had a comment back .... didn’t realise it would be that much!
probably why I haven’t had any pricing or payment issues for a very long time