Why Does the Estimate Always Go Up After the Work Starts?
People are psychologically incapable of walking away from something they have already torn open. The number climbs after work starts because of: 1) the sunk cost fallacy, once your kitchen is in pieces you will pay almost anything to close it 2) anchoring, the low bid was never an estimate, it was a reference point built to beat the honest guy 3) commitment and consistency, you already said yes once, and saying no now feels like calling yourself a fool. The cheapest bid is not a bid. It is a foot in the door.
Why this keeps happening
Low number wins the job
Demolition removes your exit
Every surprise arrives after that
The final price was the real price
The real comparison
Ask what the number excludes and notice which question he answers instead.