Here is an exhaust company which is right on par with Akra. Look through their offerings, which are a piece of art IMO. Lambo, Ferrari, Maserati, Bentley, high end Audis. You will be hard pressed to find an exhaust higher than $6K (with the twin-sound Lambo exhaustr being the exception).
At the end of the day, the end cans of the 1///M are fairly primitive relative to what is required to analyze, design, construct, fabricate, and deliver a complete exhaust for the above cars. If the buyer base ^^^ ain't paying more than $6K on $200+K cars, who thinks buyers of a $47K car will be paying $6K on an exhaust...
2011 BMW E82 1///M: AW, ZPP, ZCV, HK, Sirius, Apps; Akra CF+Valve control, MadDad mids, K&N, Forge FMIC, P3gauge, EuroTails, Tint, CF Mirrors+Spoiler+Roof Wrap, 10mm H&Rs, IND grills+gills, xCDV, LUX AE
2008 Audi B7 RS 4: Sprint Blue, Exclusive Euro Recaro Interior, Premium+Titanium Package, EPL Tune, Stasis Ohlins MS coilovers, Milltek valved exhaust+DownPipes, Stoptech SS lines, Tint, ADR V1, Lidatek, Lamin-X, Rotiform SNA 19x10" wheels, 275/30/19 PSSs, Euro flat-bottom steering wheel, JHM SSK