I just did some price comparrisons. I checked Sanderson since they make headers for very low volume custom applications such as shorty headers for a small block chevy in a '37 Ford. On average their V8 shorties are $285 for plain uncoated steal and for an additional $150 you can have them Ceramic coated. Total price $435

I would prefer ceramic coated plain steal over stainless because the stainless always shows some rust especially around the Welds and Ceramic coated headers hold the heat in much better and reduce underhood temps.

Another advantage to plain steel is that if you are welding from pre-made curved pieces you have a larger selection of pre-bent curves in steel than stainless.