How much will it cost me to get out of my 3 year Contract with Rogers?

I have had my contract for about 1 year and a half. and i bought a iphone on craigslist. and now i have the data plan. But my brother canceled his plan with rogers and he had his plan for about the same time as me. and he had an iphone too. it cost him about 100$ only, but i wanted to know just to be exact how much will it be. and i just called wireless wave and they said it will cost me 500$ but i didn't buy my phone with rogers so i think it would be about 100$ but i am not sure. please reply to my question.