You can go to your local thrift stores, like Goodwill, for really cheap clothes. They'll probably cost around $20 for all of them. You may need to adjust the color of the sneakers by using fabric, paint, or craft foam and add that yellow lines and cuff to the jacket.
My Facebook Cosplay Page~
Cosplays For 2013/2014
Asuna Yuuki (SAO): 90% ~ Gou Matsuoka (Free!): 95%
Aqua (Kingdom Hearts): 65% ~ Yuri Nakamura (Angel Beats!): 20% ~ Sayaka Miki (PMMM): 5%
Cons I'm Attending
TigerCon, NekoCon, VA Comic Con