IMO for the Garmin vs alarm clock example, it's less about costs and more about power & branding. The retailer & the wholesalers involved all have a reasonable

IMO for the Garmin vs alarm clock example, it's less about costs and more about power & branding. The retailer & the wholesalers involved all have a reasonable idea about what people will pay for the products in question. The portion of that final consumer price that stays with the retailer is just the result of negotiation. The retailer can likely buy decent alarm clocks from anyone, so alarm clock makers & wholesalers have no pricing power and the retailer can demand high margins. But the retailer can only get Garmin from Garmin. If Garmin has done a good job promoting the brand, such that the retailer feels they have no choice but to stock it, they will have to suck it up and accept low margins.