Originally Posted by
eigenvector
Probably not as Japan is a fairly expensive country for hotels and food. If you save $100 on your flight it isn't going to last you more than a day or two.
Definitely not for $100 if you're evaluating on a cost-only basis, but Japan can be surprisingly inexpensive. Not always as much as during my first visit, when 100 yen was about $0.82, but I've stayed at capsule hotels in Hiroshima and central Tokyo for about $19 and $25 a night, respectively.