@inthehands my closest contender:
$30k to convert a brilliant collection of JMP scripts generating daily manufacturing metrics in a fab to PHP2, rather than $700 for JMP to be installed on a new host.
JMP is stats software, with a mix of brilliant matrix, query, stats and graphing functionality. PHP2 did none of these well. I was averaging 6 lines of new code per line of original, was guaranteed to burn thru the budget, and had no idea how I was going to effectively debug self-rolled equivalents to selects, and graphs with error bars, etc, nor A/B compare my output against original. I said so to the CIO, and mercifully got fired off the task as it was cancelled.
See why I see resemblances? Bonkers idea, bad scoping, unlimited hubris, etc.