i think in bittrex, the fee is 0.001 btc too because the last time I am trying to withdraw in early of august, I see the fee is 0.001 btc but I don't know how much the fee now. I am not to active for withdraw because I only withdraw if I need money so I think you need to make sure the fee first. I think the other exchanges is different than bittrex but I am not sure about this.