PORT CHARLOTTE, Fla.—The steakhouse at the sprawling new Sunseeker Resort Charlotte Harbor serves $52 lobster linguine, $100 crab legs and $195 prime Tomahawk rib-eye for two.

Such pricey fare is no shocker at a waterfront hotel. But the name on the joint might be. Maury’s Steakhouse is named after Maury Gallagher, a champion of cheap travel as the CEO and largest shareholder of Allegiant Travel, parent company of budget airline Allegiant Air.

Sunseeker is Allegiant’s long-awaited—and much-debated—entry into the hotel business. The 785-room resort, a few years behind schedule and $300 million over budget due to the pandemic, Hurricane Ian and other factors, opened Friday near Punta Gorda in southwest Florida.

Why is a Las Vegas-based budget airline getting into the luxury hotel business in Florida, let alone with a property that doesn’t have a beach or a major hotel affiliation? “Where the hell is Port Charlotte?” is a question Allegiant has heard from the start.

No other U.S. budget airline is doing this. Major airlines don’t own hotels these days either, except to train employees. Allegiant says it simply wants a bigger piece of its passengers’ vacation budgets and other Florida visitors’ wallets. It flies nearly eight million passengers to and from Florida every year, nearly two million through nearby Punta Gorda Airport alone.

A bigger slice

Until now, Allegiant has only gotten travelers’ airfare—flights from Chicago to Punta Gorda this winter are as low as $38 one way—plus fees for baggage and other extras and commissions from vacation packages booked on its website.

It has mentioned Disney as a model for getting more than ticket revenue. Today, you’ll find a pop-up on Allegiant’s website offering a Sunseeker vacation package when you search for flights to Punta Gorda, Sarasota and St. Petersburg.

The big unknown is how many of those passengers will shell out hundreds a night to stay at Sunseeker. Allegiant executives say their passengers love cheap flights but aren’t cheap. Many already stay at luxury resorts at other Gulf Coast destinations.

“Now we have a product that is every bit that and more,” says Micah Richins, president of Sunseeker Resorts. He is a former Las Vegas executive who opened the 5,000-room MGM Resorts on the Vegas Strip 30 years ago this week.

The resort offers 785 rooms. Photographs by Mikaela Martin for The Wall Street Journal

Sunseeker says it sees guests coming from three major groups: Allegiant passengers, tourists flying other airlines or driving to the area, and group meetings. Sunseeker has convention space and a private golf course. It’s the second-largest hotel to open in the U.S. this year, according to CoStar Group, behind only the new Fontainebleau Las Vegas, which also opened last week.

To size up the $720 million resort I’ve been tracking since Allegiant announced its plans in 2017, I checked into Sunseeker on opening weekend. The Wall Street Journal paid for my last-minute, two-night stay, and I didn’t tell the resort I was coming. I paid $288 before taxes and fees, thanks to a promotional offer I found. Other paying guests I talked to paid about $300 a night.

The closest hotels nearby, a Springhill Suites by Marriott and Four Points by Sheraton, were charging around $220 a night last-minute. For weekend stays in February or March, Sunseeker is quoting rates of $500 to $600 a night on its website.

Forget Allegiant

The first thing you notice at Sunseeker is the scant mentions of its parent. The airline’s in-flight magazine is the travel guide in each room and there’s an ad for Allegiant’s loyalty program on the back of one of the buildings.

The only place the Allegiant name sticks out is in Sunseeker’s sports bar. It’s called Allegiant Stadium, after the Las Vegas NFL venue the airline bought the naming rights to in 2019. It was the busiest place at the resort last weekend, with long waits for tables.

“We’re very aware that as an airline that advertises low fares, a reasonable person from day one might ask themselves, ‘How upscale is this property?’ ” says Scott DeAngelo, Allegiant’s chief marketing officer.

No one will mistake Sunseeker for a budget hotel. It’s a destination resort with two Las Vegas-quality pools, one of them adults-only, a food hall with 11 outlets, and six stand-alone restaurants including Maury’s and Allegiant Stadium.

The food hall felt like an airport food court at times. But it was great for a quick coffee, affordable breakfast ($12) or takeout dinner for the room. The center bar was always packed.

Maury’s was worth a splurge in money and calories. (Its au gratin potatoes, $15, are not to be missed.)

My room was large, with floor-to-ceiling harbor views, a 65-inch LG TV, a Keurig machine with pods and a big bathroom with Lather toiletries. Guests receive glass water bottles, with hydration stations on each floor. The main thing missing: bathrobes. (Those are only available in Sunseeker’s condo-like suites.)

The gym is among the largest hotel fitness centers I’ve seen, at 7,100 square feet, with dozens of Technogym machines and water views.

I didn’t make it to the spa. Utah executive Alicia DeFinis had a massage during her three-night stay and wasn’t impressed with it.

“No locker room. No hot tub. No showers. No nothing,” she says. She did enjoy her massage.

She and her husband booked their last-minute stay at Sunseeker on the advice of a driver who picked them up from the airport. They asked for recommendations for a kid-free getaway. They had flown Allegiant once, but weren’t aware it was opening a resort.

They wished there were more activities at or near the hotel, but loved Maury’s, the hotel service and the pools.

Richins says the pools had to be spectacular to make up for Sunseeker’s setting away from the ocean.

“We recognize that we are a harbor property and not a beach property,” he says.

Sunseeker was surprisingly impressive, even if bad weather prevented a dip in or drink at the pool. I probably won’t be back on my own dime because I’m a beach freak. When I think of Florida, I think of beaches.

DeFinis, who runs a home products company, says she would return.

“We don’t love sand,” she says.

Photographs by Mikaela Martin for The Wall Street Journal

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Write to Dawn Gilbertson at dawn.gilbertson@wsj.com