with bsm, i recently bought 10 hours for £220. i seriously suggest using recomendations from friends etc though. i had a private instructor before i moved and she was perfect for me, my new bsm one isnt but i dont yet know enough people round here to recommend to me! if you can, do that.
its cheaper. but also, my instructor was explaining to me how most people dont last long with aa/bsm etc is because they make more going private so theyve no reason to stay with lousy bsm/aa. furthermore, the only reason SHES staying with bsm is because she never intended to do it for long! so thats the jist really - all the pro drivers are out private.
people might disagree with me, but thats my take.