Can you help me find a place that can provide a price list for frozen vegetables?

I'm filling out a claim form to get some of my money back from a shipment that went bad. I can't get the claim started until I can come up with a proof of value on my shipment.The shipment was 6 qts. of purple hull peas, 6 qts. of cream peas, and 2 quarts of blackberries all frozen.I need a price with a professional letter heading on it with the cost of frozen vegetables.Is there a website to look for?