0000950133-00-003168 S-3/A 3 20000802 COSTAR GROUP INC 0001057352 7374 522091508 DE 1231 S-3/A 33 333-39490 684633 2 BETHESDA METRO CENTER 10TH FLOOR BETHESDA MD 20814 3012158300 2 BETHESDA METRO CENTER BETHESDA MD 20814 S-3/A 1 s-3a.txt COSTAR GROUP, INC. EX-5.1 2 ex5-1.txt OPINION OF FRIED, FRANK, HARRIS, SHRIVER EX-23.1 3 ex23-1.txt CONSENT OF INDEPENDENT AUDITORS