One thing I've learned from working in different fields, which seems to hold true for all business: If a client approaches you with a dumpster fire of a repair job, are too broke to get a real fix, and get agitated (or simply ignore) by the talk of what the job will cost - simply tell them "sorry, I can't help you with this one".

99 out 100 times they will be a hassle, and you'll be lucky if they pay you anything beyond the upfront payment.

Even worse if it is another business, as the author writes, those can just declare bankruptcy and walk away.