Buying replacement ac adapters, when that is possible, is usually extremely expensive. Can you provide an example? Apart from some kind of weird branded ad

Buying replacement ac adapters, when that is possible, is usually extremely expensive. Can you provide an example? Apart from some kind of weird branded adapter, I find this implausible: I can find dozens of both model-specific and universal adapters under $20 on Amazon... What is the solution to the plague of missing ac adapters? Someone must have figured this out? I can think of a couple lower-tech solutions: * devices in some domains have de-facto standardized, for instance 5.5x2.1mm barrel plugs for guitar pedals * devices in other domains have switched to USB connectors, especially if they don't need more than the default 5V@500mA * keep the devices and the adapters together, instead of splitting the adapters into a drawer