Sage 50 US

Hello, I am trying to set my software up to pull up the last paid price for individual customers when items are input in a sales order. I haven't been able to find anything that says that we can do that in Sage 50 US. I have found a couple of things…

I have several customers that for only certain items are charged lower prices. How do I calculate and assign different price levels to the same customer? Example: Customer 1 has Items B, F, G, H & J at a discounted price and the rest of the items…