Change quantity discount price - repost

For products in my PrestaShop 1.5.6.2 are different quantity discounts defined. For example: - The normal price for 1 item is USD 10.-- - If you buy more than 9 items, you get a discount of USD 1.-- per item, so you have to pay USD 9.-- per item see on [login to view URL] at the moment the best price is diplayed on [login to view URL] and an [login to view URL] Your job: 1. On the product page it shows the discount per quantity and the reduced price per quantity. When the user change the wanted quantity, the right reduced price as to be displayed above add to cart (at this time this price is for qty 1 and is static) 2. It must show the best price possible (which is the lowest price -> most quantity discounted price) per product on this 4 blocks/places: - BEST SELLERS - FEATURED PRODUCTS -Category-View (Product-Listening) (the best price is already dsiplayed but my modification seems to be not compatible with BEST SELLERS) - Search-Result (Product-Listening) [login to view URL] must add to cart the qty corresponding to the price displayed on those modules Important: I can give you access to my shop to do change, but I would also need to get changed file in a zip.