Old article price

Hi Thimmo, I wanna ask you if there is a way to show the old price. What is old price?
Example:
a basic tshirt with print does cost 15€, I add my provigion ( 10€ ).
Now the price is 25€ for article.. but today I wanna to make a discount offer to my customers, and I renunce to 5€ of my provigion, now the tshirt costs 20€ ( but up the actual price you can see the old one )

There is a way to work on code and show it? It’s important, because my ccustomers, your customers ecc ecc may see the new and old price, and feel real the discount..

https://ww.wp.xz.cn/plugins/wp-spreadplugin/