Canon 70-200mm f/4: An Impulse Purchase

I've been seriously considering the purchase of a Canon EF 70-200mm f/4L USM especially with the current rebate going on. So when I heard on DPChallenge that Amazon is doing double rebates (possibly inadvertantly) I jumped at the chance to pick up the cheapest Canon L (for luxury) at a good used price.

Why am I, a poor grad student who tries to save every dime when it comes to photography equipment, buying a $490 lens (after rebates)? The short version is I'm thinking of going Pro (well, maybe not pro, but making a little money). The long version will have to wait another week or two to come out.

But, needless to say, I am extremely excited. I love new hardware!

I did super-saver shipping though, so I'll need to wait two weeks to get it :(

[Update 5/21: The lens shipped today, it will show up tomorrow, AND the sale is still on. Amazon's page listing the discounts is here. Current detail page here.]