I worked in an electronics retail store long, long ago. Our highest profit margin product was in selling extended warranties. Our second highest, in accessories. Cables, adapters, batteries, universal remote controls, and so on. My employee discount allowed me to purchase items at store cost. Just for illustration, an $80 set of Monster Cable patch cables cost me $16. I'm sure the profit margins on Audioquest cables are similar.
Re: subwoofer placement, yeah, it's probably better to start a new thread to ask about that. This Audioquest thread makes my skin crawl a little.