Honestly, the odds are so stacked against the idea-man that doesn't have the technical resources to be heavily involved that I don't know if it's worthwhile to do the development in the first place. First off, the standard boiler-plate contract with the developer will grant that developer full rights to the project if the idea-man can't or doesn't pay him, so the developer could end up profiting off of a finished product even if the idea-man contributes a significant amount of professional knowledge to the project. Second, the idea-man will effectively have to write pseudo-code to explain functions of the profession to the developer, so if he doesn't come into the project without at least a modicum of programming knowledge he'll poorly convey what the developer needs to do, even if he is an expert in the profession. Third, he won't be able to himself maintain the project as accounting rules and other laws change that dramatically affect the product, so maintenance will continue to be a problem.
Without already having some development experience I don't see this really working.