If you want something as bad as a Macro that repeats keys without any knowledge of whether a spell has been casted, or if its still on cooldown..then yeah buy a silly mouse macro, you will go nowhere with it.
If you want a good macro, check this video out:
that macro is by far faster than any mouse macro, as well as it takes in consideration your current cooldown/cast and in a version being built right now it will make sure that no spell will ever skip.