save your money, the ef 15-85 f3.5-5.6 IS USM is a great lens for a 1.6x body, kinda pricy but you can find it used for cheap (~$550) if you are willing to wait. that would be my choice, awesome video lens for skiing park and pretty much everything else.
but if your really into photography maybe your money would be better spent on an L series lens. you can get a used 17-40 f4L USM for about the same price.
IF i could go back to when i bought my first slr body i would have shelled out a bit of extra cash for a better lens, 500 seems steep but it will afford you to choose from many great starter lenses that will still be useful to you when you are no longer a beginner.