There are cheap and easy solutions, they’re just not very accurate. You can build a model in Excel in an afternoon, but it’s just as likely to mislead you as it is to give you accurate insights.
In our experience, it requires either huge amounts of compute resources (training an AI model) or lots of human time to get to a model that accurately reflects reality. At Recast we’ve spent the last 4 years working on automating and speeding up that process but it still requires a lot of intense effort to get to a valid model for any single customer.
Our mission as a company is to make the technology for doing MMM better and better so that we can drive the cost down and make it accessible for brands of all sizes, but there’s still a long way to go.