I guess in a way, I'm surprised Apple hasn't ported aperture to the PC. I've heard a lot of good things about it, but I've never had the ability to try it, because I don't own a Mac.
You can get better deals on Lightroom, but you might be saving $50-75, not a huge difference - unless you or a child are a student at a university with significant student discounts.
You can also try LR3 for a month for free from Adobe if you think you could swing it in a month, just as another option.