I've recently bought via eBay several desktops and laptops from a nice outlet in Calgary. Great prices, a fraction of new retail. And these items are new enough that their performance is much better than we're used to: e.g. i5 processors in the 3+ GHz range. You'd have to pay a great deal more to match their performance.
And they generally come with Windows 7 Professional, part of our 'Ignore Win 8 Until They Fix It' program.
There have been a few minor glitches along the way, such as the loose heat sink, an incorrect disk drive, and a bad RAM stick. But everything is working out great.
I'm learning a great deal about IT Support along the way. Reinstalling Windows from the iso download (legal), diagnosing RAM faults, all the new Video Port standards and converting between them, etc.