Different qty discount for different customer type

Is it possible to create one set of quantity discounts for one group of customers and a different set of quantity discounts for a different group of customers? For example, can we give retail customers one quantity discount and give wholesale customers a completely different quantity discount? We give our retail customers a quantity discount in a fixed dollar amount ($7 off when you buy two items, $10 off when you buy three items, etc.). We give our wholesale customers a percentage discount (35% off 5-9 items, 40% off 10-20 items, etc.). I know we can set a minimum quantity for wholesale orders, and we can set a wholesale price for each individual product, but that doesn't seem to cover our situation since our wholesale prices vary depending on the quantity ordered.

Thanks for the quick reply. I was hoping we'd be able to use the cart to process our wholesale orders along with the retail orders, but I guess we'll have to stick with taking the wholesale orders via phone/email and manually inputting them in Authorize.net instead. (The cart has been handling our retail orders for several years. I don't know why it only occurred to me today to wonder why we'd never tried to put our wholesale orders through it too.)

Is there a way to accomplish this by assigning a product to more than one category and then giving each category a different set of discounts? (For example, apply the fixed-price discounts for quantities 2, 3, and 4 to one category and apply the percentage discounts for quantities of 5 or more to the other category, and then assign the products to both categories.)

Or, could a product be assigned to a sub-category, and then one type of discount applied to the top-level category and the other type of discount applied to the sub-category? Or in that situation would one discount override the other?