Replying to Need Ski Boot Help Please

Ok. My mogul coach just figured out that my boots are horrible and they are unsafe for my bindings and they are probably the main factor for me popping out of my skis so much. I initially thought it was just my ghetto crappy bindings I had going. But my boots right now, they are super worn on the toes and the heels which makes it not want to stay in the binding well. But right now, he wants me to fork out $400.00 for new ones... but I just bought new skis, bindings and a team suit, plus the club fee. And I cannot spend any more money on gear. Do any of you guys know of any good mogul boots that I can get for used cheap? Like some older ones off ebay. I don't really know what I should do. Please gimmi some ideas. thanks.