TL;DR I coded my art school's ERP in 91,000 lines, in 4 weeks, with Claude Code. My dashboard valued it between €230,000 and €430,000. A weekend earlier, I had just understood that a five-figure consulting package signed a few months before with a commercial ERP vendor was worth nothing to us anymore. Here's how I discovered that the "lines × day-rate with AI discount" method will not survive a