Payment rules (my custom setup)

My products are all set to a fixed price of 1 euro and I have only Paypal (for now)

My rules are:
For 1 product the total price is 1,40
For 2 products the total price is 2,30
For 3 products the total price is 3,20
For 4 products the total price is 4,00
For 5 products the total price is 5,00
For 6 products the total price is 6,00 ............etc

In other words:
if a customer buys 1 product only then the price must be PLUS 0,40 cents
if a customer buys 2 products only then the price must be PLUS 0,30 cents
if a customer buys 3 products only then the price must be PLUS 0,20 cents
and if a customer buys 4 OR MORE products then the price must be 1 euro for every one of them

Can someone please help me implement this simple set of rules?

My fault! didn't say it right in previous post.

The customer buys different products (one of many) and not a lot of the same (many from one)
So, the total payment must be calculated during checkout at the cart...

It's like a fee added if customer buy just one or two or three products, and no-fee if customer buys more than three ( >=4)

It should be easy but ...is it?

Is this -major- feature missing?

My problem should be solved if somehow there was a system to add fees (like handling or something else) to the shopping cart in co-junction with how many products the customers puts in the his cart (or something like weight or mass). This system should calculate the extra cost for small buyers and benefit larger customers with free "handling" fees. I think Virtuemart has this feature for free (if I remember correctly)

My products are downloadables ...so does not involve shipping or anything like weight or mass ...and so, the fees should be for "handling" the order... ...this is what I'm thinking .....any suggestions??

For reference:
extensions.joomla.org/extensions/extensi...emart-shipping/22495
extensions.joomla.org/extensions/extensi...emart-shipping/23261

Yes, I see that HikaShop is indeed very powerful...

but, how can I set it up like I want? (first post) ...Some help please!

That was easy... I just didn't click on "restrictions" before ...thought it was for groups only!

Thanks! ...now I just have to find another word for "shipping" ... ...

By the way, ...how can I hide the quantity column of "cart module" AND the main cart/checkout page ?
(( downloadables don't really need quantity! ))

Thanks again! (happy!)