The average U.S. wedding costs $34,200, according to wedding planning site The Knot. Pop-up and micro-weddings top out at $5,000. That $29,200 gap is driving a measurable shift in how couples structure one of the largest single-day purchases of their lives.

Bethany and Sean Smalley of Wisconsin planned their San Diego ceremony in six weeks through Simply Eloped, a full-service company that packages officiant, makeup artist and photographer into a single booking. Bethany's requirements were direct: a good backdrop, minimal guests, no stress. Simply Eloped handled the rest.

"I wanted to look good, have a good background, and be with like minimal people, and no stress," Bethany said.

Sean was equally blunt. "I wasn't looking to go into years of debt for, you know, a few hours on a special day," he said. The Smalleys attended with family only.

The mechanics of a pop-up wedding are straightforward. A couple names a location and date. The vendor secures permits and insurance, sets up chairs and an arch, and provides an officiant. Los Angeles-based wedding officiant Alan Katz runs the same model.

"They just tell us where they want to get married, give us the date and time, we get all the permits, the insurance, we set up the chairs, the arch, boom, they walk down the aisle, they're married," Katz said. "They don't have to do a thing."

Venues are typically beaches, parks or public spaces converted into ceremony sites for a single day—the source of the "pop-up" label. No banquet hall deposit, no catering minimum, no multi-year venue waitlist.

A survey by Shane Co. found 14 percent of newlyweds said they were too stressed to fully enjoy their wedding day. That figure gives the cost argument a second dimension: traditional weddings are not just expensive—a measurable share of couples report not enjoying them.

The numbers on traditional wedding spending track closely across sources. One industry figure puts the current U.S. average at $36,000, slightly above The Knot's $34,200—both figures reflect a market where venue, catering, photography and florals each carry five-figure price tags before the guest list expands.

For the Smalleys, the pop-up format delivered on every requirement Bethany set at the start. Sean said he has no regrets.