Costco Japan has the LIXIL INAX RG2CST Shower Toilet Seat for ¥18,800 (¥17,407 tax-free). The Costco Japan item number is 585148.
Toto Washlets are readily available in the US, but I think they start around $250-$300. I haven't noticed other Japanese brands in the US, but there seem to be a lot of brands that I never heard of before.
Thank you - I reached out to Lixil on FB to see if they sell in the USA and confirm the products are made in Japan and not China. I've never seen their products in the USA, everything here seems to be Toto, vastly overpriced and the export models are probably not made in Japan, or cheaper no-name models made in China, such as what they sell in Costco over here.
Some of the larger H-Mart Korean markets have a few imports from Korea we may look at as an alternative if we can't find the right machine here.