Adding extra fee to a discount?

I have a product that I want to sell it in a higher price than usual to a specific customer.
i.e. the standard product price is 100€, but I want to sell it for 150€ once to a specific customer.
So, I want to add negative discounts (OR something like an aditional fee to the product price, using a coupon, or affiliate link). Can I do that?
Or shall I look for a different way?
I don't want to create another product.
My nopCommerce version is 4.30

You can use tier price for that customer role https://docs.nopcommerce.com/en/running-your-store/promotional-tools/tier-prices.html
Or you can try this negative discount plugin. But don't know about specific customer feature present or not https://www.foxnetsoft.com/nopnegativefee