Being a new service and asking for 100 EUR as a minimum for CC deposits and 300 EUR for SEPA is not a good way to attract users. I suggest you change that.
We'll see... Hope, it won't be necessary.
Also, the calculation of your fees seems to be broken. I believe you're not taking into consideration the "In fee" while calculating.
You enter what "You'll pay" and immediately see what "You'll get" -- all counts are real, incl. all fees.
It's really important for us -- if You'd be so kind to tell what count did You enter?