You have to pay £50 for the exam as what I gathered from some of my Filipino work colleagues who already took the test. They said it was only up to 25 questions (if I heard it right) but there might be some changes and they will add the number of questions, I don't know, hopefully not. You could get a reviewer to scan and study before getting the test. My work colleagues said that the 2007 Edition of reviewer is the best one to get. If you are not so confident of a self review, I browsed the net earlier I came across a site that offers a course, training and certificate for the Life in the UK Test. Click here for details. If you want to practice the test like you are in the actual test day, with a timer and some useful questions, you can do it in a free on-line practice.
It's nice to do it all, buy a reviewer or go to a course training if you have the money and if it assures you can pass the test. But well for me with a little tight budget, I need to pass the test in August by self review and borrowed reviewer!hehe..I know God will be with me and I still have plenty of time to review..
Hope this post will be useful to you ;-) xx