@OP: I just visit your site, it looks great, simple, and pretty easy to use. What I want to ask though is about the exchange rate. As I see you have 1BTC=10016.2€ when the price is ~9830€. This difference is because you include in your exchange rate the Processing fee (3.6%) and the Service fee (3.4%)?
Yeah, I made simple calculations and it seems the service fee and processing fee have an impact amount of crypto you will receive if you try to buy at the indicated exchange rate(I think the exchange rate already takes into consideration the slippage rates or that Buy and sell price gap)
I do the same calculations and fees look to be included in the exchange rate. I thought though to ask the OP to verify our simple math.

Also, the blockchain fee (0.0005
BTC) is the same with almost all exchangers and I suppose that is not included in the exchange rate.