Not to be the party pooper, but the rim width is really old school. Aero matters more than weight virtually all of the time, and you can get full on modern 50mm wheels for 1300g for c.700 USD w carbon spokes. So if you're building a hill climb bike, then sure, but for virtually every single biking application, you'd be better served with a wider rim, a 28C tyre (if not more), a good rim to tyre interface (aka, a wide rim), and a good spoke shortening device (aka, a deep rim).
Unless you actively want to go slow, ofc. Some people take pride in spending good money to buy bad performance.
And it's been shown many times, but 1kg difference up a climb makes virtually no difference, so 300g...