Until the Peerless Assassin made a huge splash they didn't have any competition who undercut them by a lot. All of their competition was generally within 20% of their price for similar performance and quite frankly so long as the colors aren't a bother Noctua's fans alone are easily worth that price difference.
The current market is nothing like the market they released all of their coolers into. As it is their most recent non workstation/server coolers have all been cheaper models. I certainly don't expect Noctua to start making budget coolers, but there's no way they aren't aware of the market and set their sales expectations accordingly.
Probably consider the mounting system as well, SecuFirm/ SecuFirm2 seems highly praised. I wonder if there are comparison sites reviewing that aspect between brands, if there's more dramas or whatnot getting the thing on with cheaper alternatives.