Mayor-elect Marion Barry, whose underdog campaign in the District of Columbia initially drew only benign neglect from the city's major campaign financiers, wound up raising more than $500,000-2 1/2 times as much as Mayor Walter E. Washington reported seeing in the 1974 elections.

According to nearly final reports filed Monday with the D.C. Board of Elections and Ethics, Barry raised $5088036 and spent $489,424-including $331,036 and spent $489,424-including $331,385 in media and printing costs-in his September primary and November general election campaigns.

Barry's campaign committee spent more than 8,000 for transition costs, contributed $3,000 to the D.C. Democratic state Committee, donated $4,000 to a joint fund-raising affair for his two primary opponents (Washington and Sterling Tucker) and also gave $1,500 to one-time opponent John L. Ray, who eventually withdrew from the Democratic race and supported Barry.

Despite all these payments, however, the Barry organization still has $18,562 on hand and no major outstanding debts, according to the report. Campaign treasurer Max Berry said Tuesday that some of the surplus money would be used to pay a final campaign telephone bill and some of the rest probably would be given to the state committee.

The latest report, essentially covering the past six weeks, indicates that Barry received 28 contributions of $500 or more and 23 additional donations of $1,000 or more. This included nearly $8,000 from organized labor groups.

Barry's contributors included serveral city employers whose jobs could be at stake when the new administration takes office Jan. 2.

Among them were Knox Banner, director of Business and Economic Development, who gave $50; James L. Jones, director of the Office of Youth Advocacy, $110; Personnel Director George R. Harrod, $50; mayoral staff assistant Eileen Hemphill, $20; M. Brent Oldham, chairman of the Board of Appeals and Review, $50; appeals board executive secretary Clinton L. McDonald, $500, and Virgil C. McDonal, assistant directr of the Department of Human Resources, $20.