Discount variant error

-- url of the page with the problem -- : www.viviemozioni.it/sabina-lumache/lumac...nte-da-cucinare.html
-- HikaShop version -- : 2.6
-- Joomla version -- : 3.4.4.
-- PHP version -- : 5.6
-- Browser(s) name and version -- : chrome
-- Error-message(debug-mod must be tuned on) -- : xxxx

Help me.
Hi, the product page when I insert the variants appears the initial price and then discount is negative.
The page reference is:
www.viviemozioni.it/sabina-lumache/lumac...nte-da-cucinare.html
If I put the price of the product screen backend and the variant, the price did not appear as an option in the original file version.
Example:
product 1kg Price not granted € 20.00 Discounted price € 10.00
Variant:
1) Product 5kg Price not granted (where I go inside?) Discounted price € 30.00
2) Product 10kg Price not granted (where I go inside?) Discounted price € 50.00
I do not understand because it lacks a field
Help

hello Nicolas, certainly not make myself clear.
The problem is not in the file-listing price that I disabled as you told me, but the problem is not solved.
The problem is that in the backend can not put the price without discount variant. Some time ago I managed and I send you the link where you can see that it worked:
www.viviemozioni.it/tempo-libero/dettagl...on-della-tuscia.html
How do you see the price for 4 people is € 80.00 and the sale to the public is 24.90.
I added a new product variants:
www.viviemozioni.it/sabina-lumache/lumac...nte-da-cucinare.html
and I can not put the original price variants, that I would put 5kg € 60.00 and € 45.90 discount price. I can not find the field where you enter € 60.00.
Thanks for your help. I attach screenshots backend

Let's continue only on this topic:
hikashop.com/forum/product-category-disp...discount.html#222379