They've only got 5.86% so far and are falling short of their needed 350 thousand. (They're at 3.09 thousand.)
I don't want to see them fall short of their goal.
However, if you cannot spare ten dollars, do not feel bad. There is a Donating While Broke link on the "About" page at NaNoWriMo. You can donate to NaNo by using the GoodSearch search engine.
You can donate part of the proceedings if/when you auction items off at eBay.
However, if you can spare ten dollars (and I emphasize the can), then I strongly urge, plead, beg even for you to help out. Think how bleak November will be with no National Novel Writing Month!