Another option is craigslist. I bought my latest Mac Mini - 1.83 GHz Intel Core 2 Duo Mac mini (Mid 2007) - a little over a year ago off of Craigslist for $375. The seller had originally listed it at $850. At the time I remember that a 1.83 C2D Mac Mini was $599 on the Apple store ($579 w/ a student discount) and a refurbished 1.83ghz Mac Mini was $499 when available. I used that to bring it down. It was just a couple months old and so had original warranty until October 2009. Had a few upgrades too ( little more RAM, bigger HD). In 2006 I had bought a Mac Mini G4 which was a similar situation.
Curious, the two updates that have occured since my mid 2007 model, how much better are those mac minis than the one I have?
I'm actually looking for a home computer right now (left the Mac Mini with my family) and debating on getting something like a mac mini again or stepping up to an iMac or even a Mac Pro. My primary computer is a 2007 MacBook Pro (2.2ghz C2D SR) and I'm upgrading that later this year to the latest MacBook Pro. The home computer will be a secondary computer for me and my wife (hers is a MacBook Air)
I posted this earlier and saw feedback from Bacong & steve2112. Seems the Mac Mini that is out right now is a lot better than the one I had purchased used off of Craigslist in early 2009 - I think right before the update. But I did purchase it for a little under $400 so I think I made out pretty good.
The following's a little long but it's me sort of thinking everything in my head too.. but if there's any comments, please chime in.
I'm in need of a home computer (left the 1.83ghz C2D Mac Mini and the Dell 2408WFP 24 inch Monitor with my family) and am wondering what route to go. 1) if I should do the same thing I did before about looking for a fairly recent, used Mac Mini on craigslist still under warranty for around $400, then pick up a monitor. Or 2) get an iMac.
My primary computer right now is my 2.2ghz MacBook Pro C2D SR which will up updated this year (I sell my MBP before applecare's up) and my wife's primary computer is her macbook air (she'll have this for up to two years). If I got a better home computer, I would look into doing more with it - some video editing for me, and my wife probably would start getting into photoshop. The problem is that in looking at the iMac, from the threads I'm reading seems the better ones are worth it so I'm tempted to get the i7 quad core which is currently $1850 refurbished (should be just tax on top but after I sell the free printer I should end up back around 1850).
A high price but assuming I got a monitor on the caliber of the 2408WFP - Dell 2408WFP 24 inch Widescreen Flat Panel Monitor (whatever is on that level today), I think I'd be looking at around $500 or so which is what I paid for the Dell. Add that to the $400 or so I'd expect to pay for the Mac Mini unless I get the better Mac Mini which would probably be closer to $600 on craigslist (have to figure out if better mac mini is worth it).
If I do the iMac, the mods on the list would be an SSD swap of the 1TB HD and putting in a blu-ray. I think I cold do an SSD on a Mac Mini but not sure what I could do w/ blu-ray for a Mac Mini - probably external?
So I'm basically looking at $600ish or so price difference between a) a recent, used Mac Mini and nice, large monitor versus b) 27" iMac i7.
Any thoughts? after typing all this out.. I think the extra $600ish could be justified as long as we did a lot with the computer
!! So I would like to hold off a few more months until these come out. 
