The BA pilots are fascinating and full of historical facts, but they tend to be woefully out-of-date. I'd say if you found a couple in a used book store for a couple of bucks, they make a nice, nautical addition to a bookshelf. For actual useable info, I'd use the net - CF, noonsite, etc.
BA has the best worldwide chart coverage, but I wouldn't have the first clue where you could find them cheap
. I guess it really depends on how much coverage you desire.