Ridiculous... only in the sense that it it is a $500 bike
That has had $500 worth of gold leaf put on it.
For a total of about $1000
And is being sold $300,000

And, why would one use rim brakes on rims that have had gold leaf applied?

If one is going to go for outrageously expensive, at least start with a nice base, such as this 2.9kg (6.4lb) featherweight, or the Merida Scultura 9000 LTD at 4.55 kilos (10 lbs). Or, maybe some super aero styled bike.