This is usually the issue that arises when you wander from 'I'm completely new and I breed whatever I can' to 'I have a rough idea what I'm doing now and would like to work on a personal project'. Of course there are people that swoop in and only do it for profit, but it's also a part of becoming a breeder in the Addict-community. It's a natural step.
Something I always remind myself of is the Red Tabbie. It was overbred, like intensely so, in the beginning. No one wanted it anymore. Today? It's sought after, and the newer people can't believe that such a pretty fur was so unwanted. Even if someone copies you and the market gets over run with traits. If YOU like the trait, then continue working on your line. Be patient. Your cats are going to be priceless down the line. And since you spent the time on it, and not just copy to mass-produce, they are gunna be some amazing cats and people will value them even more because you actually took the time and energy to make it into a dream cat. Don't worry about the now, think of the future!