From Nintendo Life
"The Japanese-Language System" is priced at 49,980 yen (approximately $333.87 USD at the time of writing), versus 69,980 yen ($467.48 USD) for the Multi-Language equivalent, which will only be available from the Japanese My Nintendo Store. The base system will retail for $449.99 in the US.
Why the different tiers and prices? This option has presumably been made available as a reaction to the weak yen, which makes Switch 2's launch price even harder to swallow on Nintendo's home turf than elsewhere.
The ability to play games from any region on any Switch 2 around the world makes importing a Japanese console very financially attractive for people living outside the country, so language-locking this cheaper version aimed specifically at the Japanese market will dissuade people who don't speak or understand Japanese from importing the cheaper model.