NEW YORK (MarketWatch) -- A U.S. defense-budget request from Congress for new business jets has drawn fire from the Pentagon.

"Whether the funding is added to the budget or taken from somewhere else, it ultimately comes out of things that we believe are more important," said Geoff Morrell, a Pentagon spokesperson. "And once we get saddled for additional planes we didn't ask for, then we have to find where in the budget we can cut to fund their operations."

As first reported by The Wall Street Journal, House representatives want to purchase two modified Gulfstream 550 business jets and two modified Boeing BA, +1.15% 737s for a total of about $550 million. The request was an add-on to a Pentagon request for one Gulfstream 550, built by a unit of General Dynamics GD, -0.41% , and one 737, along with a request to purchase two 737s currently being leased.

No one from the House Committee on Appropriations was available to comment Monday. The request now has to be approved by the Senate.

The Department of Defense in the midst of adjusting its priorities, dumping some high-cost procurement programs to fund a fight against insurgents in Afghanistan and Iraq. It comes as the U.S. is facing a greater budget deficit due not just from the wars, but from large bailout packages to firm up the country's financial and auto industries, shaken by the global recession.

In June, Congress seemed to recognize this new reality and voted against additional funding for more F-22 fighters jet to free up more cash for the F-35. See full story.

A good deal in the long term, but it could come with a political cost

According to the Air Force, only the modified Gulfstream would be used to transport members of Congress, and only on official trips.

Laurence Korb, a former government official and now a defense budget analyst with the Center for American Progress, said Congress was likely fed up with having to postpone trips due to there being too few aircraft.

"These are for official Congressional trips only, it's not to take them home for the weekend," Korb said in an interview. For example, "this is for a group of House members who want to go to Mexico to [study] the war on drugs or something else."

"But what has happened is that this has become symbolic of the earmarks and all the other things people have concerns about," he said.

And it makes Congress look hypocritical. Last year its members expressed outrage over auto executives that took private jet flights to Washington D.C. to ask for bailout money, saying then it symbolized Wall Street and corporate excess.

But putting aside from the budget spat between Congress and the Pentagon, purchasing the new jets could also be a better deal for the country in the long run, given the age of the current fleet of Gulfstream III jets that Congress uses now. Those aircraft have been in service since the early '80s and have extremely high maintenance costs.

In an August report from Aviation Week, the upkeep for a G550 is about $5,093 for every 1,000 nautical miles flown, while a GIII is about $9,556.

So for every 10,000 hours of fight time, the G550 would save taxpayers about $45 million, said Nick Tarascio, Chief Executive of Air East Airways Inc., a flight services company in Farmingdale, N.Y.

"It's comparable to buying a new house versus buying an old house," Tarascio said. "It's a bigger initial investment, but over time it's a better deal ... it's a more efficient way to operate."

The G550 is more fuel efficient and has improved technology compared to the GIII, Tarascio said. Additionally, the G550 makes less noise than a GIII, allowing it to fly into more airports and at any time.

Then there is the cost. Business jet demand has plunged in the past year due to the economic recession, encouraging dealers to lower their prices.

According to Ascend, an aerospace consultancy, the price of G550 has fallen more than 27% in the past year to $42 million from $58 million, though that cost doesn't include any "value-added materials" such as secure communication links and cushy interiors.

For the Air Force's part, it would buy the jet for $66 million after adding on its hardware, which likely includes a lot of advanced military technology.

An Air Force spokesperson couldn't provide a breakdown of its cost.

The House may have considered all of these things when it voted for the jets, but it can also be seen as a way to put some of their constituents to work.

Business jet manufacturers, including Gulfstream, having been laying off workers as the demand for jets have declined. The jets Congress wants to purchase are assembled in the U.S. with parts made primarily in this country across 29 states, said Robert Baugniet, a spokesperson with Gulfstream.

Only the engines, made by Rolls Royce (RR) and part of its tail are made overseas, he said.