I've got 3 forms, Customer, Product, Quote

Quote is comprised of Lookup fields Customer.Name, Product.Name and I want it to get the Product.Price field from the Product Form. 

So to generate a quote I will only need to select Customer from a drop down, select Product from a drop down, then the price of that product I've selected will be automatically filled into the third field.

Any ideas about how to go about this, it seems a simple thing to do but I have limited experience with the scripting side of it so I'm a  bit stuck.

Thanks!