Depending on location but luxury Ryokan can be anywhere from $300 per person per night and up. Typical popular Onsen (hot spring) area Ryokan where rate is $150 - $250 per person per night, local Japanese say those are nice Ryokan but I do not think local Japanese will say those are luxury Ryokan. Ryokan is priced by per person, not by per room. With two people can easily end up spending $500 – 600 and up per night at luxury Ryokan.

I have one concern about OP trying out luxury Ryokan. If Ryokan experience did not turn out in positive way, then I think that will be big waste of money for OP, isn’t it? If I spent $100 - $150 per night and a hotel ended up not to my taste then I can brush it off. But if I spent $500 - $600 per night… Will OP end up upset and feel total waste of money if Ryokan experience did not turn out to be positive?