From Bloomberg, AAPL Acquisitons since 1990:

Date * Type of Action Summary

2/ 4/97 Acquisition Target: Next Computer Inc

9/ 2/97 Acquisition Target: Power Computing Corp

4/11/00 Acquisition Target: DVD authoring software

3/14/01 * Acquisition Target: PowerSchool Inc

7/ 9/01 * Acquisition Target: Spruce Technologies Inc

4/ 4/02 Acquisition Target: Zayante Inc

7/ 1/02 Acquisition Target: eMagic.com LLC/Germany

12/ 4/06 Acquisition Target: Proximity Corp

4/23/08 Acquisition Target: P.A. Semi Inc

Even better: http://en.wikipedia.org/wiki/List_of_acquisitions_by_Apple_I....

Contains prices - biggest one was NeXT for 400M and then PA Semi for 278M