Even if you live somewhere dense, there’s so many niche things, no brick and mortar place stocks it. For my own router, I had to find one recommended by forum users a decade ago for a specific disconnect issue within the Xbox One’s internal 360 emulator. BB and WM didn’t have the known-good options. In my recent case here, it was hobby stuff that my local craft store doesn’t have at all, despite carrying similar items. And I mean my classic example is I used to dabble in LEDs before everyone was just buying mains bulbs and 12v strips. The price of a single blue 5mm LED in the hobby electronic store was the same as 100 on ebay.