Because the product you found is not a wholesale price.
I know of a wholesaler that sells strivectum-SD for for $89 Bucks
For a 6oz tube.
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They are a wholesaler of this product so you will have a minimum purchase requirement. But I dont see much profit on an items such as this for you.
As you probably already know ebay sells most items at wholesale or even below wholesale if too many sellers are selling the same product. So companies that actually buy from the manufacturer stand to make the most profit on these types of items.