NEW YORK (MainStreet) — Every day you dither in booking airfare for a July 4th getaway is going to cost you. That is the hard hitting message from Adam Goldstein, CEO of online booking site Hipmunk.

He puts dramatic numbers on this. According to Hipmunk's data, travelers who booked July 4th air in 2013 during the week of Memorial Day paid on average $417. Those who booked three weeks after Memorial Day paid $547, which is a 31% premium.

Every day counts. Those who booked a week after Memorial Day in 2013 paid $444. Those who booked two weeks afterwards paid $471.

Goldstein is adamant that this year, because July 4th falls on a Friday, demand will if anything be higher as many of us decide to get out of town for a three-day weekend.

Good fares will be hard to find after June 1, said Goldstein in an interview with MainStreet.

That warning is stern. But hold on before rushing off to book travel right now. Hipmunk competitors have different outlooks, and - crucially - frugal advice may be utterly otherwise when it comes to booking a hotel room for a July 4th getaway. Keep reading to get the full picture.

For example: a spokesperson at Kayak.com said you may have a little more time to score the best airfare: "We recommend booking travel within the U.S. between three and seven weeks out, as prices gradually increase two weeks out until the day of departure."

That would give travelers some slack. Three weeks from July 4 is June 13 - meaning that if you believe Kayak you may have two additional weeks to book. But their advice also suggests that booking sooner just might be smarter. Said Kayak spokesperson Maria Katime, "If you find [an] airfare you're comfortable with, you need to book it right away."

At Hopper, a travel search company rooted in Big Data analytics, data scientist Patrick Surry flatly said: "The longer you wait to book travel, the more you will pay."

Hopper envisions a busy July 4th - it estimates air traffic as 60% more popular than it was over Memorial Day.

You probably will pay a premium if you are flying into Las Vegas, Orlando, or Los Angeles, the three most popular July 4th destinations, per Hopper.

But Surry seemed unconvinced that now is the last moment to score good deals.

He elaborated: "Prices start rising more quickly in the last two weeks" -- and we are not in that crunch-time yet. Not quite.

Bottomline: twists and turns aside, the research strongly suggests that buying July 4th airfare very soon is the best strategy. Can you wait until Sunday night? Sure. You may pay a bump in price but it won't likely be substantial. Keep delaying, however, and you will get hammered. That is certain.

Airfare sorted, what about a hotel room?

The advice is the exact opposite: sit on your hands, do nothing.

That's because the big surprise is that there is no advantage to booking a hotel room now for July 4th, said Goldstein. "We are seeing more last minute rates from hotels," he said, and those rates, usually, represent big discounts off so-called rack rates (list prices).

Why? Hotels know rooms are like milk - they spoil fast, and an empty room has no value. Most want to fill every room and, as the date nears, they panic and begin discounting especially through channels where the pricing is "opaque," meaning it does not show up in Internet searches and, therefore, will not establish a deflated benchmark for what fair pricing for a room is.

Don't airlines face the same challenges? Yes. But they have better data scientists than all but a handful of large hotel chains can afford and, then too, said Goldstein, hotels face so much more competition and that makes for a market that is more Wild West.

His advice? Unless you have your heart set on staying at XYZ resort for July 4th, hang tight and always, urged Goldstein, do your last minute hotel hunting on your smartphone. Why? "We are beginning to see many cases of lower prices for the same last minute room over mobile than we see on a desktop computer," he said.

Read that again, it's blockbuster stuff: mobile Web and apps users are seeing cheaper prices on their devices than are desktop computer uses, according to Goldstein.

Be cool and, almost certainly, you will get a prime room in your destination city for significantly less than those hotels are demanding today. Wait until they blink - then pounce with your mobile phone.

At Hipmunk, last minute bookers see discounts of as much as 60%, said Goldstein, and that kind of savings is absolutely as American as July, 4th cherry pie, and a sky filled with fireworks.

--Written by Robert McGarvey for MainStreet