[Bring_Back_Shantz]

Looking at the sunk cost is silly.
If you don't like what you're doing, what difference does it make how much money you've spent on it. That money is gone, and the only thing it can do for you now, is get you closer to doing something you don't want to do.

If you want to try something new, make the decision based on the merits of what it is that you want to do, not how much you've invested in something you don't want to do.