> I think the more pertinent point

Not sure it is. Unless the Saas company is ripping you off (sure it can happen - but hopefully competition in the market would manage that over time ), then it won't be that much different from your own maintenance costs.

I always think if that's the business case for custom software ( a few quid license cost savings ) then you probably shouldn't be doing it as there is almost always a better ROI case for transformation through custom software.

So back to the bakery case. Is the benefit savings on license costs, or the fact that you can give much better estimates to customers, better de-risk supply chain issues, hire less people to operate, and improve morale via reducing busy work?

All these sort of things have to be more valuable than a few quid on licensing.