About ecomix.io
I don't know from where you got that percentage of fee (0.3%) which i didn't find it. I tried that mixer and pay more than 3% and today i tried to open two new session without completing the mix and i got two other different fee costs:
First session: Your personal fee is 1.55088% + 0.00007 BTC for every forward address
Second session: Your personal fee is 1.34974% + 0.00007 BTC for every forward address
I think their fees is variable but it's clearly sure that it is higher than 1%.
Looks like you (somehow) missed the big "Service fee" slider that lets you choose how much want to pay in the first page of the mixer (where you can select anything from 0.3% to 4%), and as low as 0.00001 BTC as a transaction fee. For a total of 0.3% + 0.00001 for every forward address. Way lower than this mixer's minimum 1% and 0.00008 BTC for every forward address.
Here is a screenshot:
