msOptionsPrice
Component for setting additional product prices based on characteristics
The component adds option-based prices to products (e.g. by size or other attributes).
Edit settings under "System settings" with filter "msoptionsprice".

After enabling the module, a new "Options–prices" tab appears in the MiniShop product resource.



Wrap the [[!+price]] placeholder in a span with class pr_change so the price updates when options are selected:
<span class="pr_change">[[!+price]]</span>