President Donald Trump joked Tuesday night that the $5,000 payments he's promised U.S. adults would buy little more than "a hamburger and maybe a small dessert" at his Mar-a-Lago club in Florida, a week before midterm elections dominated by voters' concerns over affordability.

Trump has pledged $5,000 to every adult citizen if his fellow Republicans retain majorities in both the House and Senate, specifying the money must be spent in the United States,

"Go to Florida, go to any one of our great places. You can even come to Mar-a-Lago," Trump said at a rally in Texas.

"The problem is that for $5,000, the most you'll be able to buy is a hamburger and maybe a small dessert."

The president also joked that, "I'm not even sure you could buy that."

"No, don't go there. That's not a good place if you're price-conscious."

Affordability has been a dominant issue for Americans heading into the Nov. 3 vote.

The CNBC All-America Economic Survey this month of 1,000 registered voters found that 55% said that prices for them and their family are rising "faster than usual."

When asked which issues are the most important facing the U.S., with two answers allowed, 34% said "the cost of food and groceries," while 23% said "the price of gas." The top concern was "government corruption," at 36%. The survey found that voters believed Democrats would do a better job than Republicans on gas prices — by a 9-percentage-point margin — and food and groceries, by a 16-percentage-point margin.

When asked their preferred outcome in the congressional elections, 52% of voters said Democratic-controlled chambers of Congress, a 7-percentage-point margin over Republicans. That is a 4-percentage-point increase since the survey was conducted in July.

Some economists have warned that one-time direct payment to Americans would do little to ease affordability pressures, and could exacerbate inflation at a time when many people are already feeling strained. Prices for necessities like gasoline and groceries have been a particular pain point for most U.S. households.

Sending $5,000 to every adult citizen would cost roughly $1.2 trillion and require Congressional approval.

The president has also in the past made similar promises of delivering cash payments to Americans, which did not materialize. Less than two months before the 2020 election, Trump pledged 33 million Medicare beneficiaries $200 prescription-drug cards "in coming weeks" — but the cards never went out.

The president's White House renovation has also become a campaign-trail foil. Speaking at an Ohio rally last week, former President Barack Obama said Trump had "got the White House looking like Saddam Hussein opened a Cheesecake Factory," saying, "there's gold everywhere." 

On Monday, Trump defended his White House redesign and blamed Obama for failing to address the needed repairs.

"Guys like Obama don't see it. You don't see dirt. He doesn't see filth. He doesn't see broken ornaments on a building ... And for you to say it's a Cheesecake Factory, that just shows why you were a lousy president."

—CNBC's Davis Giangiulo and Dan Mangan contributed to this article.