The little known secret - products on amazon are often more expensive than found elsewhere. They charge a 15% - 30% commission fee per item sold, so majority of retailers raise their prices when listing on amazon. The category my company sells in has a 20% commission fee, so we raised pricing by 25%, and our volume of sales on amazon was not effected.
If you find a product you want, and a decent price on amazon -- try googling the seller's name/brand and see if their website comes up... the same item will likely be there cheaper.
We've found that people trust the amazon platform so much, they get blind to pricing. Most also don't realize they are not buying from amazon directly - but often a 3rd party seller. Most large sellers don't use the FBA either (where amazon warehouses your products for you, for a fee).
Also, recently amazon changed their minimum commission structure -- to be a $1 minimum for any product sold under $6. This effectively destroyed the penny book sellers, as well as many other industries that sold cheap but high-volume products (like my company does). So... now we've changed to sell more quantity per unit sold on amazon (case/pack sizes). So now, effectively there are no "cheap" $6 or less products on Amazon.
That's much easier than trying to locate these items on a handful of different websites, signing up for new accounts and payment systems. It's also easier than going shopping downtown, finding a few items, but not the others, which means I need to place an order online either way. And if I need to place an order online, I might as well get everything on Amazon, so I qualify for free shipping.