Oh, you can get pretty interesting combinations at low levels. Fell Weaken is quite funny - Fell Weaken Acid Splash for example deals minor damage and -4 Str penalty, which stacks with the one from Ray of Enfeeblement. Not much low-CR monsters are that efficient with more or less 8 points Strength penalty. Fell Weaken Acid Splash means a negative level for a 2nd level slot... more than nice at low levels. And Extend Spell is bread and butter for low-level clerics.