If you wanted "new old stock" or "refurbished computers where you felt like there was a tiny bit of security that what you would recieve would work - there was Tiger Ditect.

• You wanted an IBM AT-Clone in 1990? Tiger Direct catalog and phone order it!
• You wanted a Pentium II widos PC in 2001, Tiger Diect woudl sell that to you one of those
• You want a discounted PDA with teh added 16MG stage modele thrown in for free....Tiger Direct!

Where do I buy refurbished machine now? Who is the cheap source of 'slightly used' office computers? I am actually in the market for a refreshed machine, but Tiger is gone - who do I turn to now?

eBay is the place to go for that now. There's dedicated shops set up on there for selling refurbished mass-produced workstations. You can get a pretty great deal on an older Xeon workstation on there if you are willing to look a bit. It won't have the fastest single core speed but you can get tons of cores for very cheap. eBay's purchase protection should cover you from any issues though if you pick a store with good feedback you should be fine.