I was mocked a few weeks ago discussing the subject of cost by using generally accepted albeit generic business terminology. Perhaps I’m one of the few who have operated and owned actual businesses on Earth but for the sake of educating my Eve family, I’ll soldier on.
Cost and price are closely related but not the same. The price of materials at trade hubs might be your (OP) cost but they certainly are not mine but merely represent a referential basis. My cost of production is the amortized cost of the mining equipment and skills I purchased now used to mine ore. As such my cost structure is less than one tenth of yours and I can easily make profits far below the referential material prices (basis) posted at trading hubs.
Players that buy material at trading hubs, then construct products for sale at the same hub are merely engaging in arbitrage. In this case the relative cost of production is more a function of trading in the individual component bid/ask spreads than anything else. In actuality, since Eve is virtual, it’s all arbitrage except (virtual) mining is one (virtual) integration removed. With highly liquid and efficient markets, bid/ask spreads and arbitrage prospects are small.
So when you see finished products selling at prices below the aggregated imputed component cost on a trading hub basis, it’s not manipulation but merely a different cost structure and the minimization of arbitrage potentials.