Another way to ask "why has the price not fallen after almost 2 years?" might be "why should Samsung drop prices on their product after it's proved itself for 2 years by still being arguably the best of the best of this kind of product on the market?"
Of course it's a price monopoly: vendors always demand highest prices on their highest-demand products/services, prices won't drop until demand drops. Samsung 850 SSDs are now a common cornerstone in consumer and enterprise platforms, people keep buying them at Samsung's prices so Samsung will keep selling them at Samsung's prices.
"All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Adams
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