That's unfortunately what a lot of headers have cost and then some, for a long time now. Guess it depends on how frugal or spendiferous they think the vehicle owners are going to be. Or just how low volume they expect them to be, and still want to stay in business.
Those look pretty sweet and have a couple of design characteristics that I wish other headers had. For me I still prefer the smaller primaries though.
I remember back in about 2000 when I stopped by a shop here in Burlingame and they were about to install a set of $1200 headers on some kind of a Chrysler sedan-ish thing.
I was kind of taken aback that regular street folks had to pay that much for their regular old street cars for headers. Maybe at the time they were first to market and could price them at just about any level. Or they were just that much harder to design and manufacture.
Not to mention having to have them certified for smog compliance (If they'd done that) and such.
I only really knew what Mustang and Chevy pickup headers were going for at the time, so it was real sticker-shock.
I'd hate to even think what one-off custom headers would cost these days.
Paul