Ebay usually beats Amazon’s prices if one can find the same product. Amazon is trying to use distributors of every product there is to make Amazon a one stop shopping place.
It depends what you want to buy. The same Chinese flashlight that cost 1.99 at Ebay will likely cost 5.99 on Amazon, while a Logitech M100 USB Optical Wired Mouse costs $5.99 w/ free S+H, at Ebay but 4.89 at Amazon, while a can of Great stuff Big Gap Filler, 12 Oz costs $10.06 & FREE Shipping at Amazon but only $4.64 at Walmart. While expect to pay at least 14.99 for reg. 30x30 dark men's jeans at Amazon or Ebay, but only 9.99 at Walmart (fairly heavy).
Bingo. I got out of the habit of going to Amazon first but as a last resort. I dont like Bezos and Amazon isnt always the cheapest.
Yup, go to Amazon, learn about the product, read the reviews and then head over to Ebay to buy it, usually cheaper and without tax.