Just to be a bit more specific about the price, you can see on this page.
https://ricohimagingstore.com/gr.html
The Urban Edition Kit, even though it includes the strap, extra black lens ring and metal hot shoe accessories, costs a thousand yen less than the standard GR IIIx without them. The prices here look expensive when you convert to dollars, but there are some mitigating factors that sweeten the deal. By buying from the Ricoh store, you get a 3-year warranty. If you go for the packages that cost 140,000+, you get that extended to a 5-year warranty. Also, when you buy, you get 10% points towards your next purchase, and if you are paid-up member of the Family club, that rises to 13% (standard) or 15% (premium member).
I'm wondering if this is a mistake, because the price relationship doesn't seem logical. But another possibility is that there will be a general price reduction to make the standard models cheaper with the new direct sales regime for Japan. Anyway, for now it seems you would be crazy to buy the standard model unless you really must have black.
Personally, I'd go for grey to distinguish between my black 28mm model and the grey 40mm model. Since the two cameras look almost identical, there is a practical reason to go for the colour variation if you have both.