The commercial version of JWebPlus is $35.00 and has 300 or so questions. A couple of guys from my office used that exam simulator and the
servlet and
JSP specs, and the O'Reilly JSP and servlet books. They did ok on the exam, but they felt that they spent too much time delving into details they didn't need to know for the exam.
After flipping through my copy of the Manning book, one proclaimed that it was a better deal than a $35 test simulator and 2 $40 books, and only goes into the detail required for the test.
I do not plan on purchasing the commercial product based on my collegues comments.
David