Countdown is £49.50 for 12 weeks, or was when I purchased mine. But that still sounds right, as the weekly fee is £4.95 and you pay for 10 weeks, get 2 free. I'm not sure about the 6 week countdown price - they still do it, but I was only looking at 12.
Books are covered by your joining fee, which is currently free with that voucher as already mentioned. Unless you mean cookbooks, which vary depending which one you want. Should be a price list in your group's shop. Last one I bought was £5.95 which is about the middle of the pricing from memory.