If you are unhappy about how the discounts are displayed, I invite you to uncheck the “Display discounts?” option and add your own text in the product description.
Concerning the price calculation, I need to know exactly what you are trying to do in terms of pricing in order to help.
Here’s how it works right now on your website when you select Saturday-Sunday-Monday:
Total price is 850€ (300 + 300 + 250)
First two days are full price (850/3*2 = 567€)
Third day is -20% (850/3*0.8 = 227€)
Total is 794€
I understand your issue but unfortunately it’s how it works. Duration Discounts doesn’t pay attention to which days are selected, only duration. I know it can be improved, but it requires a lot of work and time so it can’t be done immeditatly.
I’d be happy to offer you a refund if it’s not what you need.
Do all your products have this pricing scheme? Because if you want I can give you a custom hard coded solution while I figure something better for the plugins. It’s not ideal but in can work in your particular case.
Please send me an email at firstname.lastname@example.org telling me if you are insterested (so I can send you an updated file to try) or if you want a refund 🙂