Making Discounts Add to price

Hi,
  Do you mean the discounts as can be set in the admin panel under Marketing > Quantity Discounts ?

If so, possibly the easiest way is to set a positive discount, adjust your base price UP by 10% and swap the wording on the  screens around. I've NOT tried it  and you may need to experiment with wording, or even customizing the  screen that displays  the product  prices to get it looking how you want it to.

If this is not the correct discount then please let us know.

As regards customer psychology - they always prefer to see a discount instead of a service charge, or, second best, just wrap the  10% service charge into the base price.

Another option is to add it as part of shipping - but if customers don't become aware of an extra 10% until checkout then you are likely to have quite a high cart abandonment rate imho.