This applies to all RAM.

The cost of 16GB Raspberry Pi is driven by the RAM. Everything else is a small addition to the BOM cost.

The 16GB was introduced when it was affordable. Now it's just becoming a mental obstacle for buyers who think they should only purchase something if they can get the top model. That's why I suggest everyone pretend it doesn't exist. Unless you really need it for something, the 4GB or 8GB can do most things.