No idea. I just googled a bit and pulled some numbers from a few different bulk suppliers I found (all in China). Perhaps competition from china has had a dramatic effect on prices?
Or they're bullshit suppliers advertising ridiculous prices and wares, like the company advertising kilograms of stuff only made on milligram-scales since it was discovered (don't remember where I saw that, probably the comments of a "things I won't work with" entry)