Your 100% correct...
If you look at any Header and midpipe combo from Kooks or ARH its around $1500 give or take for a Complete system. The headers are around $800-1000 then the midpipe is another 400-600+....There is nothing wrong with paying this much for quality and a product that works. There are so many benifits to having longtube headers for performance and longevity of your engine. Your reducing cylinder pressure, releasing an extreme amount of heat from the motor, and lowering restriction. The design of the headers, the bends and length of the tubes is where your making power. Alot of companys slap some tubes together and put a "longtube" header out there on the market that fits like shit, was made in china, and costs half as much as a quality system such as Kooks or ARH and then it wont make as much power or torque because of the lack of design and knowledge in building a real performance header. They are out there so if thats what you want then hey.... But personally I would only put one of these two companys exhaust on my car, especially since besides all that they are made in the USA!