Apple's online store currently has the refurbished Mac mini with Snow Leopard Server (model no. FC408LL/A) for $749.  That's $250 off the original price of $999, and the lowest price we have seen on this Mac model by $90.  FREE shipping is included and sales tax applies for residents of most states.  The Mac mini features a 2.53GHz Intel Core 2 Duo processor, 4GB of RAM, dual 500GB hard drives, a NVIDIA GeForce 9400M graphics card, and it comes pre-installed with Mac OS X Server Snow Leopard. 

MacConnection.com has the same Mac mini with a 2.53GHz processor, 4GB of RAM, and dual 500GB hard drives, in brand new condition for $819 with FREE shipping.  Also available at Apple's online store is the 2.66GHz Mac mini with 4GB of RAM and a 320GB hard drive for $719 with FREE shipping.  The brand new Mac mini with a 2.4GHz processor, 2GB of RAM and a 320GB hard drive is now available at BHPhotoVideo.com for $668.95 with FREE shipping.  While this article was being written, Apple's online store updated their stock of refurbished Mac minis, that now start at $429 for the 2.0GHz Mac mini with 1GB of RAm and a 120GB hard drive.  A $300 price drop can be found on the 2.0GHz Mac mini with 2GB of RAM and a 320GB hard drive, now $499.