How can I create negative discounts?

[Daniel Halpern]

Hello all!

The thing is as follows.
I have a wedding invitacion site, where the prices are for each unit, and shown for qty's of 100.
But if a client add's 50 un to the cart, the unit price MUST raise in order to have the real price.
Is anyway to do this?

Example:
Card 1 worths 1,5usd for 300 units
Card 1 worths 3usd for 100 units
Card 1 worths 5usd for 50 units
And the price shown in the store is the one in the 100 units.


Thanks for any help!
BTW, this is the site: www.magentainvitaciones.cl

[Daniel Halpern]

Any one?