I got paid for the initial versions, but not after that, while it made almost all my other work much easier. When paid by the hour, that isn't an advantage :)

Not necessarily. Because you're reusing and thus cheaper, you may get more contracts. You may be able to command more money per hour as a "premium" for fast, reliable service. Depends on how you describe it to the client ("sell yourself"). You may be able to do both - command more per hour than your competitors, but still come in cheaper overall. And, with your spare time that you have in abundance, you can find more contracts. :-)