If you don't care too much about the price, the time difference is low: you spend some time looking at an online retailer (maybe typing in your address), but you save the time you would waste searching Amazon for the correct listing amongst all the knockoffs, sent-from-Hong-Kong etc.

If you care a lot about the price, you already need to consider other shops, since Amazon isn't necessarily the cheapest anyway.

I have ordered one thing from Amazon in the past five years, where the manufacturer only sold to consumers through Amazon.