Not just that, but MS Office is 10 times better than Open Office or other free packages if you actually do use the advanced features. We use every feature of Excel at work, and Open Office can't even compare. Pivot Tables, Subtotals, Goal Seeking, Solver, Multiple Linear Regression through the Rinlex plug-in, Conditional Formatting, and heavy VBA automation. Even Access is invaluable as a front-end for our Oracle and Siebel databases.
I'll admit, however, if all you need an office software suite for is word processing and basic spreadsheet calculations (come to think of it, most people tend to use Excel inappropriately where a table in Word or a simple database would be better), then MS Office is complete overkill.