Even though the 1980 census will cost roughly four times more than the one in 1970, taxpayers probably won't get much more information for the nearly $1 billion expense, government auditors say.

The government spent approximately $222 million on the 1970 census, which furnished population statistics and other information that the census-takers gathered about U.S. citizens.

An investigation by the General Accounting Office shows that the cost for the 1980 census might well approach $1 billion, when inflation and other factors are taken into account.

Some $300 million of the added cost, for instance, is directly attributable to inflation and to a larger workload in 1980 because of increased population.

The introduction of new procedures will account for approximately$400 million in additional costs over the 1970 census, according to the GAO, the auditing arm of Congress.

Its report noted that the Census Bureau wants to reduce the population undercount, primarily for minorities, and improve the quality and usefulness of the data.

Of the 1980 census, the report said, "Many of the planned coverage improvements overlap . . . The bureau recognizes this but believes it is necessary to compensate for limitations in individual procedures."

Comptroller General Elmer B. Staats is quoted as saying: "For the 1980 census, the bureau plans to spend more than four times the $222 million it spent for the 1970 census without assurance that there will be appreciable improvement in the data collected."

And in a section of the report titled, "Should the census cost $1 billion?," GAO investigators write that the improved methods the bureau plans to use to try and count all Americans are complex. It said these procedures are "all without certainty that the gains in the count will be of the anticipated magnitude."