Actually, no, you can't. Its $321 on Newegg and exactly 300 on Monarch. And the Opteron 165, which is even slower than the X2 3800+ is $355., On the other hand, the 3000+, which is the same clockspeed and the same performance, is less than half the price at $125...
Like I said, for something thats pretty much useless until games for it come out (6-8 months), its not worth twice the price.