Unfortunately it is true in the US and in Japan. Luckily for me my Japanese wife thought it absurd and never insisted on it and thought it stupid even today. She was happy with the small ring I bought her some 23 years ago and wore it proudly on our 25th anniversary the other night! I think I paid about 200,000 yen at the time which is a lot less than it is today. At that time it was about 1 months salary.

On the other hand there are materialistic women of all cultures who will insist on the "norm" of a few months salary! If that is so important to them then they would not be the type of woman I would desire to marry.