Five quid is very good. Well done!The Karate of Shotokan is my first choice. It seems more trustworthy for some reason. Each class is a fiver. The location is a five minute walk away. They teach two classes each week. I have made contact and will try a class tomorrow evening.
Make sure you go to your first class with your left trouser leg rolled up to your knee and a mango for your new teacher. It the Japanese tradition