0000950133-00-002052 10-Q 3 20000331 20000515 COSTAR GROUP INC 0001057352 7374 522091508 DE 1231 10-Q 34 000-24531 631521 2 BETHESDA METRO CENTER 10TH FLOOR BETHESDA MD 20814 3012158300 2 BETHESDA METRO CENTER BETHESDA MD 20814 10-Q 1 000095013300002052-001-seq1-10-q.txt COSTAR GROUP, INC. FORM 10-Q EX-2.2 2 000095013300002052-002-seq2-ex-2-2.txt SIDE LETTER EX-27 3 000095013300002052-003-seq3-ex-27.txt FINANCIAL DATA SCHEDULE