I've been using Prime for years and I agree their shipping prices and also the items you can get shipped using prime are going down down down. Small items that are cheaper are no longer eligible, etc. I work in this industry and totally understand why they are doing it.
But it's not even CLOSE to what it once was, Prime is not nearly the value it was a year ago. I ordered from Amazon every week simply because of no tax and 2nd day air on anything I wanted pretty much, grocery items, batteries, accessories. They don't get nearly as much business from me now due to that.
I also know that Amazon LOST money on tons of transactions I did as well, I ordered a hammock as a present Overnight for 3.99 including a giant stand, I know they lost their ass on the entire sale because of that.