160 actually sounds fine. Once you get past the initial investment of tools and everything, it should get cheaper.
My first cosplay was Rinoa from FFVIII, and including the wig, it was only about $45. I knitted the duster by hand, which saved a lot of money given that the yarn was only $6, but it took about 3 months. The wig was thirty, and the fabric to make everything else was around $10.
My best tip for keeping costs down is to get a good idea of who all you plan on cosplaying, and then frequent fabric and thrift stores. If you find something you need that's on sale-even if you don't plan on using it just yet-go ahead and buy it. I know one local thrift store that actually sells fabric remnants for around 50 cents a yard, so, you should definitely find one that does something like that.