I paid 1250 for front pipes to mufller tip at windsor exhausts in mild steel.
I'm very happy with it, but if I had the chance to do it again, I'd get @trotty to make one up for me like he did for my gf's mx5.
I have a Fujitsubo 3-inch catback that I got from Japan for around $500. Then I added a Magnaflow cat for around $240. I don't have front pipes, but planning on getting some soon. Looking at various options, but I believe custom-made cost around $450.