Expensive withdraw fees on Bittrex, why?

Hey guys,

Today I'm really surprised about the crazy withdraw fees there are on Bittrex for few of the currencies I hold.

This post is not to do bad communication regarding Bittrex, it is for me the best platform to trade at the best accurate price.
But sometimes there are things I don't understand like those withdraw fees.
I know there is a network fee but no that much ...

1. New Economy Movement / XEM

Withdraw fee = 15 XEM
1 XEM = 0.24$ so fees = 3.60$ ... WTF ??

1. Ripple / XRP

Withdraw fee = 5 XRP
1 XRP = 0.18$ so fees = 0.90$
Notes : 2 weeks ago I withdraw about 200 Ripples for nearly 0 fees with Bittrex. On my Ripple wallet the network fee is around 0.1% so ... WTF ??

So if any of you have any idea of what's going on let me know please.
I sent a message to the support already to mentioned it.

Joris