Is Amazon becoming universally more expensive?

I have a dozen things on my Amazon wish list including vinyl records, a book, a chef's knife, camera tripod, a pair of shoes, a craft item, etc. In short, a fairly random assortment of items. These were added anywhere from January 2014 to two weeks ago. It's a mix of both Amazon and third-party sellers.

Most people who keep an Amazon wishlist have probably noticed that there is a notification next to the item when the price drops (e.g. "Price dropped 10% (was $19.99 when added to Wish List)"). I've noticed in the last few months that every one of the things I saved is more expensive than it was when it was added. I'm curious whether others have noticed the same thing? Is this an indication of Amazon becoming more expensive, or commodities in general, or is it just a coincidence?

(And to clarify, I don't buy things off my list whenever the price drops, leaving only expensive stuff behind.)