[1] that's assuming your vary light, climbing the whole trip, and have a terrible power output of 250w and uses 3lb which is a fair amount and even then 8.5 seconds after a 2km climb.
A more realistic 400w + 120lb rider +3% grade for 2000km then a negative 3% grade for 2000km and a weight diffidence of .3lb for 300$. End result after 4,000km is less than 5 minutes wow that's worth 300$.
[2] 1 trip using human riders hardly qualify's as measurement. But even still measurement is next to meaningless you can detect cocaine on most people in an international airport that does not mean they have had anything but the most indirect contact with the stuff.
PS: Sure if your racing professionally then things change around, but that's a tiny portion of the bike community.
When you are out riding with your friends, you typically want to beat them to the top of climb. A 2km climb is fairly reasonable for that type of climb.
You are right - 200w is low - I just used the default values. If you look on Strava, most middle-of-the-pack people post power in the low 300watts.
1.5 kg is easily the difference between a < $1000 bike and a $2000 bike. Cycling (as a sport) has a lot of financially wealthy (but time poor) people (the same people who used to play golf). These people aren't interested in the cost effectiveness of an upgrade, just weather it will help them beat their friends up a hill on the Saturday ride.
Personally, I think using ~$200 carbon fiber water bottle cages to save 30 grams is a waste of money. But the truth is that the grams they save do add up, and the weight does make a difference on hills. If you don't care about money (!) then why not spend the money....
A more realistic 400w + 120lb rider +3% grade for 2000km then a negative 3% grade for 2000km and a weight diffidence of .3lb for 300$. End result after 4,000km is less than 5 minutes wow that's worth 300$.
[2] 1 trip using human riders hardly qualify's as measurement. But even still measurement is next to meaningless you can detect cocaine on most people in an international airport that does not mean they have had anything but the most indirect contact with the stuff.
PS: Sure if your racing professionally then things change around, but that's a tiny portion of the bike community.