As a sample point for the second question:

   A coworker here studied hard a few weeks before, took the exam, and
passed it on his first try.

   - Oliver

It's about £100.

It depends on how much you already know.
In my case I had already been coding in Java for about a year and went
through the book 'Sun Certified Programmer & Developer for Java2'
(Sierra, Bates) in about 3 weeks (full-time including doing lots of
extra mock exams) and passed comfortably.  The book is excellent for
getting through the exam and forced me to learn some stuff I couldn't
be bothered with before.

About £120 and it's a piece of piss

--
Mike W