The number your lender quotes as "cash to close" bundles together money with four different destinations: the lender's own fees, third-party services, government charges, and your own prepaid future bills. Nothing about them behaves the same way, and the bundle is why closing costs feel unknowable. Unbundled, most of the mystery leaves.
The four destinations
The lender's fees — origination, points, underwriting — are the lender's revenue, set by the lender, and the part that varies most between competing quotes for the same borrower. Third-party services — title, settlement, appraisal — go to other companies; some are chosen by the lender, and the title and settlement bundle is chosen by you, whether or not anyone mentions it. Government charges — recording and transfer taxes — are what they are; nobody in the transaction sets them. And prepaids are not costs at all: they are your own insurance and property taxes, paid forward into an escrow account that remains your money.
Seen this way, the strategy writes itself. Compare lenders on the first bucket, shop the title bundle in the second, verify the third, and stop grieving the fourth — it was always your bill.
The receipt at the end
Three days before closing, the Closing Disclosure restates every one of these lines in final form, and the tolerance rules decide which movements since your Loan Estimate were legal. It is the only moment the whole picture exists on one page while there is still time to act on it. Read it against your quote — or have it read.