It's a tale as old as time that developers, particularly junior developers, are convinced they could "slap together something in one weekend" that would replace expensive SAAS software and "just do the parts of it we actually use". Unfortunately, the same arguments against those devs regular-coding a bespoke replacement apply to them vibe-coding a bespoke replacement: management simply doesn't want to be responsible…
My firm has partially transitioned through this curve. We went went from "fully externally supplied" systems, to an architecture that combines "externally supplied" (core functionality) with "low code" about 6 years ago. I would argue (as a financial manager) that that lead to a more flexible and more affordable architecture. A funny mixed bag problem arose though: the curve of business demands grew harder than that…
I love this perspective. I feel like the pendulum has swung too far back to "it's easy to build, it'll be easy to support". But to be fair, it was probably too far the other way a few years ago: "it was easy to buy, it'll be easy to have them support it".
Other than trial and error, how do you think about pricing out maintenance costs for insourced code vs purchased functionality?