WASHINGTON — It’s one of the weirder documented facts about homebuying in America: Surprising numbers of people don’t bother to shop for mortgage money, even though they could save tens of thousands of dollars through lower interest payments by doing so.

People search incessantly online to find the best deals on hotel rooms, kitchen appliances, furniture, clothing and tons of other stuff. Or they drive out of their way for the lowest gas station price per gallon. But for some reason, many go limp when it’s time to make a really high dollar purchase — getting a mortgage to purchase a house, often the biggest expenditure of their lives.

Maybe they’re shellshocked from the home search process. Maybe they assume lenders quote roughly the same rates and fees, so why bother? Maybe their real estate agents whispered in their ears that their brokerage enjoys a special relationship with a particular lender — in fact, they’re partners, sharing profits generated from homebuyer clients — and will give them the best deal around, guaranteed. Uh huh.

When the Consumer Financial Protection Bureau surveyed 5,000 recent home purchasers several years ago in the first national study of its type, it found that fully 47 percent of buyers didn’t even “seriously consider” more than one lender; 77 percent applied only to one.

CFPB researchers also found that rate quote variations among competing lenders for the same prime borrower — with a high credit score, 20 percent down payment, seeking the same mortgage amount — frequently vary by one-half of one percentage point. That may not sound like much, but the bigger the loan and the longer it continues, the heftier the dollar savings for borrowers who shop and nail down the best-priced money. Even on a $200,000, 30-year fixed-rate loan, choosing a lender quoting a 4.5 percent rate, compared…