There are some good deals on 200 TW extreme summer tires on tire rack right now, I think Kumho and Hankook in the $500 range.
For 100 TW, discount tire eBay store runs a $100 off a $400 purchase time to time, folks try to buy their NT-01 during these sales.
The maxxis victra rc-1 is priced about the same as the nt-01 and maxxis told me there will be a coupon this spring, probably 10% off.
If you are on facebook, there is a racer's wheel and tire exchange and some deals to be had; I sold some tires there once.
Good luck and if you find some let us know what you got
