If you're a student and live in a state with low sales tax, you can pretty much get a free MacBook every year if you buy in the summer (back to school sale)
Let's take the base $1,199 MBP. 1,199 - 100 student discount - 200 free iPod - 100 free printer = $799. Since you might not be ale to sell the iPod and Printer at full price, let's bump it up to $850. Last year's $1,199 MBP (refreshed 6/09 or 16 months old) are going for $800-$900+ used, probably higher a few months ago.
The other benefit is, since you are always selling after 12 months, you are always covered under warranty without paying extra for AppleCare.