From my experience, in the heyday of consumer hi-fi ('70s and '80s) there were always two tiers of gear, cost-wise. 1) Gear that you could expect a decent discount. Sometimes upwards of twenty percent, maybe a bit more. 2) Gear that you paid MSRP, and was hardly ever subject to discounting.
Examples of No. 1 were mass market Japanese brands (Pioneer, Sansui, Kenwood, Marantz, and MM cartridges from Shure/Stanton). No 2 was most famously McIntosh, and JBL. Then, 'esoteric' stuff from ARC, Mark Levinson et al. Imported 'exotic' MC cartridges were usually not discounted.
Today, you can call up your guitar store rep and ask for a discount, and usually get one. You can (or at least could) go to your car stealership and negotiate off invoice. Is it that way anymore with hi-fi gear?
With my last purchase, I didn't even think of asking for a discount on my AHB2 and DAC3 HGC. Would they have given me one? Shipping was included in the list price, so that was something. Was shipping actually 'free', or simply 'built in' to the price? At the same time I ordered two rather largish loudspeakers; both came with 'free' shipping plus what was advertised as 'white glove' handling-- two men and a truck delivered the boxes and helped with unpacking and placement. That had to be worth something.
Back in the day when you bought a 'system' from a dealer they would 'throw in' a cartridge and 'hook up wire'. Maybe a handful of blank cassettes. Probably wind up with 20% off your entire purchase. However I don't know if dealers nowadays offer 'on request' discounts. I know mainstream mail order outfits (Crutchfield) will sell you a 'scratch and dent' at a lower price. But it's nothing like guitars, where you almost expect a deal from the get-go.
Has anyone gotten a big discount on expensive gear?