This site is useful for many things, but their resale values are out of date. The best guides are the ones suggested above, especially eBay.
The "value" of something is just what someone is willing to pay for it. To arrive at a realistic value for a particular piece of computer equipment, you need to collect all the information you can from as many sources as possible. As a "fallback" position, what can you get it for at a local retail dealer? Are similar items selling on eBay, and what are the final prices in Canada? In the US? Are similar items selling on buy-and-sell, and if so, for what price? And, of course, don't forget ehMac!I still think ;Buy and Sell; forums are the best place to look for pricing. I wouldn't rely on eBay too much; some prices go sky high for more than they're worth at times.