Blowing 3 month's salary on a ring is pretty easy in Japan where 32 year old Taro is still living with Mom and Dad and has yet to pay rent or utilities once in his entire life.

Find something that you and your future wife are happy with. That's all that matters. There's no use in wearing a down payment on a house around your finger.

Also keep in mind that most Japanese women will NOT wear their engagement rings after they are married. They'll only wear the wedding ring.