We have already developed one feature in OpenERP Point of Sale (POS) for pricelist.
Previous feature was only for single pricelist which we are applying to the customer.
But now we have made some enhancement in pricelist feature with Point of Sale, in which we can assign pricelist to product with sequence, minimum quantity.
Here is the pricelist we have created for a product.
Now we will enter that product from POS Interface which has no pricelist applied as its quantity is 1 and we can check its default price as per our pricelist rule.
Now we will change quantity from Numpad. So we can see that in our pricelist, if minimum quantity is 2 then discount will be -10 (Minus 10)
In below screen we can see that if minimum quantity is 4 then we are going to discount -20 (Minus 20). So total quantity and discount given per price is also mentioned.
So this way this feature works.
You can see the video also for the same development.