In the long term, Britain may pay a high cost for last week's vote to quit the European Union (EU). That said, it could mean a low cost vacation for travelers.

Since the United Kingdom voted in favor of Brexit, the value of the British pound has fallen to the lowest levels in three decades.

"It's a great time to be in London, " Travel + Leisure News Director Sara Clemence told CNBC's "On the Money" in a recent interview. "If you are there now, if you were there last week, you saw things get 15 percent cheaper overnight," she said.

"Your hotel stay, your restaurants, your museum admissions everything."

A weaker pound means a stronger dollar and a cheaper trip for U.S. visitors, which according to Visit Britain, numbered 3.3 million in 2015. They spent a record $4.4 billion dollars.

Last week, Hotels.com said its site saw a 50 percent spike in searches for travel to Britain. So can a trip to England fit in your budget this year?

"Maybe," Clemence told CNBC. "Even though the currency changes have an effect on the prices on the ground," she explained. for hotel and airfare prices, "some of them may be changing" but "it's not like they're discounting them across the board," she added.

However, "airfares are a lot lower than they were a couple years ago. A couple years ago you may have paid $1200 dollars, now you'll pay $500 or $600."

British Airways had a "Brexit" fare sale last week, selling economy fares from New York to London for as little as $639 round-trip.

Yet Clemence pointed out the cheaper fare trend is not due to Brexit, but instead were "low-fare airlines that are going Trans-Atlantic, so they're just bringing down those costs tremendously." Wow Air and Norwegian are new low cost carriers offering flights from U.S. cities to London for about $500.

In the other direction, a record 4.9 million U.K. travelers journeyed to the U.S. last year, breaking the previous record set in 2000.

According to the Commerce Department, the U.K. was the third-largest source of international visitors to the U.S., behind only Canada and Mexico.

On the flip side, a weaker pound could mean fewer British tourists flying to multiple destinations within the U.S.

"It just got much more expensive for Brits to come here," Clemence says, and "we might see a dip in visits to places like New York and Miami and Chicago. That then might mean that prices will come down, which is good for domestic tourists too who want to visit those places."

If you do decide to make that trip to London, should you exchange your dollars for British pounds before you get on that plane?

Clemence said there were "some strategies that you can use. If you think the pound is going to go back up, and you're planning a trip, you might think about buying your currency now. Before you go."

Clemence cautioned you need to factor in possible exchange fees. Since "fees that you might pay could cancel out all the savings that you could get."

She also recommended using an ATM card or a credit card that "doesn't charge you a foreign exchange fee."

That is "generally the cheapest way to get cash when you're travelling overseas," she added.

On the Money airs on CNBC Saturday at 5:30 am ET, or check listings for air times in local markets.