The two most common questions from new road bike buyers is “what does it weigh?” and “how much does it cost?” And really, these two questions are inter-related, but the function isn’t linear. Moving upmarket from the entry-level to mid-level, bikes get a lot lighter, but weight reduction gets much more expensive after that.
Why?
Well, at the entry level, product managers are fighting to keep costs down to meet target retail price points, and that means that they have to compromise on weight. At the high-end, engineers run into the limits of materials and manufacturing to reduce weight, forcing the use of more costly alternatives.
Take for instance this alloy seatpost from a $1100 bike. It is a BRICK at 409gr. For a post more than 200gr lighter, it would be carbon fibre and cost at least $190 alone. But post 100gr lighter would have added $5-20 to the cost of the bike, which might be just enough to turn-off the price-conscience consumer, who only sees the bottom line.
This is an excellent point and holds true with many other hobbies too such as home audio. Diminishing returns.