At a cost (a TMNT fanfiction)

Every choice we make, no matter how small it may seem, helps to shape the rest of our lives. The people you meet, the friendships forged. The battles won, and the battles lost. This is something Raph, Don, Leo and Mikey are well aware of. They've dealt with so much as a family, and saved the city. Twice. They carry their baggage without much complaint, after all, someone has to do it.
In this four book series, our favorite mutants are given chances that could change their lives. But, of course every choice comes at a cost.