[std_throwaway]

The memory sticks we're talking about here also come on a PCB, so we should not exclude that cost. What use would loose chips be if they are not soldered onto a PCB? You could argue that there could be a supplier that produces working memory sticks for a cheaper price. I'm not contending that. These products, however, are unfamiliar to most people and Arduino UNO is a brand name that many people recognize. There are many cheap knockoffs of that product that may or may not be compatible. I would prefer to stay with respected manufacturers in this case.

It is true that those micro controllers are bundled with the memory. In other words, the memory also has computing power installed. A capability that some modern memory chips also include. You may argue that we should compare with those memory chips, however, in the case of micro controllers we cannot separate the memory from the computing unit and we need the computing unit for communication. Is the comparison thus unfair? Maybe.