As convenient as it is to work by the hour, that's the genesis of the problem with lowering income by using modules.

It's more work upfront, but I think you should take a look at flat-rating. My preferred approach is something along the lines of "it will take X to dollars to make this, that and so-and-so headaches go away". It's to my benefit that I've invested the time into learning good toolsets. So as long as the customer gets what is good value *for them*, does it really matter how long it takes me to make the headache go away?

(Or, raise your rates. Take attorneys for example: They read documents, and fill in boilerplates for a living and don't blink at charging $200-$400 for their time. That's all due to prior investments in education and creating the boilerplates (a.k.a. modules.)