At least make it equal to fiat value. 0.006btc is more than $260 at the moment and I think min deposit with doge for the promo is the most expensive one because it is 10k doge which worth more than $725
If all crypto minimum deposit is not being adapted with the current price, winz.io can be a casino which is not friendly casino to crypto gambler.
I gave a response to a discussion about the slot bonus so my post above is completely related to the min deposit for the slot bonus.
The bold part of your post is wrong if we refer to the general rules of winz.io about the minimum deposit. Check: https://winz.io/payments
On that page you can see that there is a minimum deposit for each currency, so you cant say "you can deposit any amount you want" because there is a minimum amount requirement.