darksidekei,
It is so very hard to answer these types of questions with anything definitive. Much is so open to personal desires.
You can find places to "eat out" unique foods from street stall type places near Ueno Koen where you can get good traditional stuff like oden for cheap (maybe in the 600 to 800 円 range) to needing a mortgage on a really first rate kaiseki dinner in what is considered a "fine" restaraunt by Japanese standards. (But that concept is pertty much true most ANYWHERE, really.)
Much the same goes for "clubbing".
I think that the aforementioned $1000 a week US for disposable money above basic rent would afford you a lifestyle that would be a lot of fun.
But that also depends on what you want to buy. I collect Japanese pottery. It would be a snap to spend $1000 US on a SINGLE piece of GOOD Japanese pottery by a good artist. If you collect real katana....... same kind of sitution. Collect rare manga or anime.... likely the same. But if your tastes and demands are simpler..... than that $1000 will go a lot further.
I think some of the issue is to set your overall budget and then plan to live within it. Unless you have a trust fund sitting in the background
.
best,
................john