Just a question on pricelists

If we add a new item, we need to create the item with its variants in products.    

If we are selling that item to our wholesaling customer and or our consignment customers then do I need to have a different price list for each price structure, and then manually add that new product to all the other pricelists.

Eg if I have different pricelists that give different discounts to customers then I have a different pricelist for each customer.  Eg customer A has 5% off our retail price, customer B has 10% and customer C has 20% off.  I would have to create a new price list for each customer with the discount in the pricing.

Then when I add a new product, I would have to manually add that product to all the extra price lists for customers A B and C.

I just want to know if this is how it needs to be done as we are adding new products regularly and have many customers on different price structures. 

Is there an easier way to offer discounts and have those discounts attributed to a particular customer?  It seems very laborious to do it by creating a new pricelist.

thanks for any help