For things like electronics components, I used to see a lot more sellers located in China who were presumably effectively drop shipping from AliExpress. Now it's almost all pre-imported goods with fulfillment by Amazon. The difference is paying an extra $2-3 bucks (basically doubling the price for something like an Arduino Nano clone) for a much faster shipping time. Sometimes that's worth it and sometimes not.

Unfortunately as a non-Prime customer, Amazon's shipping has been getting so slow that the gap is closing and it's getting harder to see their value.