Will apple replace a void iPhone 4?

okay let me first explain the situation.

My iPhone was out of warrenty after having it for more than a year. I cracked the front and back to a point where i was sick of using it, so i decided to order a conversion kit off the internet and fix it myself. I now have a white iPhone 4 which was previously black and now this one has cracked as well. I am careful with my iPhone its just that i've got really unlucky with the cracks and all. So obviously my iPhone's warrenty and what not has been void but is there a chance of apple still replacing the phone? I know if they do, there will be a cost to do so.

Any idea if they would replace my iPhone and also for roughly how much?

Thanks,

Jahid