I just checked the BTC price right now and saw in coinpayments the minimum fee is 0.0007 for withdraw which is around $9, at this value, if BTC price hits $100k you'll pay like $70 per transaction...
and that sounds weird
Actually they say :
2 We currently
subsidize Bitcoin withdrawals so you pay a flat TX fee of 0.00070000 instead of the full TX fee. This only applies to wallet withdrawals not Conversions/Payments/Commercial items.
And yeah, checking the estimate fee for next 6 blocks inclusion it's less what you would pay normally.
I honestly wonder how much they are spending monthly in fees internally, collecting coins and moving them around, at the moment probably it's on of their top expenses and it keeps growing.