The FX-55 is going for $800 on the egg. I'd sell it off and try to get maybe $700 and then either supplement the money and get an FX-60 *drool* or just take the $700 and get an Opteron 180. The FX-60 will be clocked at 2.6GHz and is almost gauranteed 3GHz with good cooling, the Opteron 180 is cheaper, and will probably clock to FX-60 speeds but not as high as the FX-60. If you're not overclocking, don't waster the money on an FX since that's all they're good for.
Myself, I'd get an Opteron 175 which is $300 cheaper than the 180, and is only 200MHz less. Overclock what you can out of it and keep the cash difference.
I wouldn't waste the money on a 180 or a fx60, I'd get a opty 165 as almost all of the new batches are soaring, mines doing 2.9 on stock vcore lidless, theres a rummor going around that the later stepping 165 is actually a binned 185, so save some cash and get a sub300 dollar chip just my .02, btw my stepping is a ccb1e 0606vpmw that I got from monarch oem last week