Hi Mario,
I'm Prashant, a traveler and Airbnb employee. I checked your beautiful listing and it seems like you've turned on the smart pricing for your listing. If your listing has a smart pricing, our system will select best price on daily basis for your listing between minimum and maximum amout you've selected. Apart from that you've selected weekend prices as well and that's the reason, there's a different price on Fridays and Saturdays.
Please write us on response@airbnb.com for better understanding and clarification. We always love to speak to Superhosts 🙂
Cheers,