Today, four days after they were ordered, PCBs that a friend had ordered online, arrived from Elecrow, but it could have come from OSH Park, Dirt Cheap PCBs, Seeed Studio’s PCB Service or PCBCart. There’s even an online service that allows you to price compare at PCB shopper.
Also today a shipment of parts arrived from DigiKey ordered the day before. Less than 24 hours from order to doorstep, including crossing the border (customs). DigiKey has a huge array of parts, but there are many more, including Mouser, Newark and again a parts finder service at Parts.IO
Not to mention 3D Printers, inexpensive Test Tools from companies like Saelig, prototypes and tools from companies like Crowd Supply, Kickstarter, Indigogo. Marketplaces for makers to sell the things they make such as Tindie and Etsy. To find unusual, discount or rare components or supplies there’s eBay, Alibaba, and AliExpress.
These are a starter list of resources, things I have come across, there are many more that I can’t remember or haven’t yet come across.
Yes, it has never been easier to experiment with electronics and embedded systems.