Hi,
If you want a way for the customer to choose the amount to pay there are two options I can see:
1. You could create a characteristic with all the different price values you want to accept and then add that characteristic to the product and then add the variants. In each variant you can then enter the price you want.
www.hikashop.com/support/support/documen...html#characteristics
This will display by default as a dropdown. In your thread subject, you're talking about a "sliding scale". So if you want to transform this into a slider, it would require some custom coding. You could display a slider as explained here:
www.w3schools.com/howto/howto_js_rangeslider.asp
and then connect that slider with the dropdown and hide the dropdown with CSS and javascript code.
2. You could also use the donation plugin along with a custom item field:
demo.hikashop.com/index.php/en/hikashop/...t-page/donation-page
A custom field could also be a dropdown, or an input field. So if you use a dropdown, you could also turn it into a slider with custom coding as explained in point 1.