That's crazy charging $50,000 just to list on their exchange. Fair enough, it will increase volume for NEM, but that is a bit arrogant to ask to pay to be listed, as they will be making money from trading fees anyway. I haven't seen anything official on their site that states you have to pay $50K, or what the requirements criteria is in order to be listed.
Many alt exchanges do the same. Considering some of the utter junk on Kraken the only explanation is that they were paid.
https://www.dashcentral.org/p/bsdev-general-201702https://www.reddit.com/r/dashpay/comments/651osc/im_thrilled_with_the_kraken_news_but_heres_the/Exchanges are out to make money and that's it. People who want coins listed on them are the same. They may as well milk them.