With this extension you will be able to offer your customers visibility on how much {they save} during different phases of the shopping process:

1. show them how much they save on the {product details} page
2. let them see again the old price in the {shopping cart's product list}
3. calculate their {total save} per entire {shopping cart}.
4. upload and go — utilizes vQmod so no core file modifications are necessary.

Demo:
http://opencart-extension.tk/index.php?route=product/product&product_id=42

For any ideas/suggestions/bugs/questions do not hesitate to make a comment, it will be highly appreciated and quickly fixed!