I recently met a man who is the son of a WWII vet. he brought back many items, including a Heer artillery side cap. I would like to make him an offer on it, but don't know what the price range of the cap would be. I don't want to accidentally make him a low offer on something that might be worth more than I thought. I am not buying it to resell, it would go into my personal collection with the k98 bayonet he sold me a couple weeks ago. I was thinking about offering him around 200, would that be a fair price? any help is appreciated. thanks!