Some products may display the message "Market Price" with a message similar to this..
"The price for this product will vary day-to-day as it is based on a Market Price, although your invoice will state $0 you will be expected to pay "Cash On Delivery" for your order when it arrives. If you would like a quote for the price of this product please contact the supplier directly via the "Ask a question" button."
This is because the supplier purchases the products each day from a wholesale market, and price is set daily. So rather then give you an inaccurate price, they have stated they will price it on delivery. Don't worry, your pricing will be loaded into you account so you can see your historical trends.
It is advised if you are ordering from a supplier for the first time that you contact them prior to your order to get a quote for which you can gauge the cost of items. You can do this simply by pressing the "Ask a question" button.
It is very important to understand you will be required to pay for the order on delivery, and even though the price may state $0, the price will be invoiced to you on delivery.