A few friends of mine work in accredited professions, and it's not something they have to deal with all that much, most likely because they are all accredited. They are billed by the hour, and typically if someone isn't happy with the cost the response is "okay, we'll down tools". Inversely, companies that bid on contracts will bid with a fixed cost in mind, and when estimates are taken that go over the requirements things will be fudged to fit the requirement in for that price. This means one of three things: corners will be cut, developers have to work faster, or requirements are cut. In my experience, the last point is a rarity.

I know that we software engineers like to think of ourselves as thought workers, and on the same level as the likes of lawyers and chartered accountants, but the way our industries operate are wildly different. I prefer to compare software engineering to a trade like carpentry, plumbing, etc. We share many similarities, such as easy barrier to entry and working on fixed-cost projects, but unlike trades, we're always willing to negotiate on our next pay day. You can say it's down to a difference in costs, but even on an industrial level where the person doing the sale isn't a trades-person, if a job requires £x and the client can only pay £y, then the requirements change or the job isn't taken on.