Let me present an axiom of software engineering: "The effort (cost) to fix a software defect is proportional to the time between defect's introduction and discovery".

Please note, that the axiom does not say "100x more", it says that cost increases (usually; it may even decrease, why not? consider a bug in ransomware that prevents it from encrypting files properly). The concrete cost may be 1.5x, 10x or 1Mx, it all depends on the circumstances.

And here's a pretty picture from the research paper on the subject: https://www.researchgate.net/figure/Cost-of-Fixing-a-Defect-...