Rather than pay Y500 a day for 22 days of baggage storage (they go by calendar days, so it usually costs one day more than you think), add Y11000 to your hotel budget. Stay for the first and last night at a decent hotel costing Y5500 a night more each night and they will store your bag for you in between for free!
I agree with the folks who suggest adding a bit more to your $2k. Adding an extra $500 -- extending the rail pass to 14 days and using the rest to improve your accomodation budget -- could make a really big difference in your comfort level and enjoyment.


3000 yen/night in accommodation will be terribly hard to find. Even capsule hotels usually charge more than that, and so do many (most?) hostels.
Don't forget to get that other rail pass BEFORE you come here. You can't get it after you arrive.
There are plenty of places for under 3000 yen, mostly hostels, or ones that will offer "dorm-style" accommodation. Here's a list of links-
Budget Travel Service
http://www.maujudi.com<BR><BR>Budget Hostels
http://www.donkey-pal.com/<BR><BR>Youth Hostels in Japan
http://www.jyh.or.jp/<BR><BR>Cheap Hotel Info
http://japaninfo.esmartweb.com<BR><BR>

Hmmm. While there are places to stay for 3000yen (or slightly less), I would not characterize them as plenty. Or convenient. As mentioned above, most of them will be hostels, ryokans, or temples with curfews. Of course, if you're not interested in night life, those options would be fine.
What are your traveling goals?
What do you want to see?
You can get a rail pass for 7, 14, or 21 days, but you CANNOT renew or extend it once you're in Japan.
If you can find someone else to stay with, this place is a great deal. It has a kitchen so you can cook and possibly save some yen on eating out. Tama Ryokan: Short term apartment rental in Shibuya

I am deeply intriged in Tokyo's nightlife. That's why i want a no curfew place. Ten ten guesthouse, in shinjuku, has none. So that's a good option i guess. I was considering the Tama, but for a single it is 4000 yen, i cannot afford it.