Here's my pitch. There are two factors to this. There is your life for the next four years, and then there is the start of your new life as a college graduate.
Most likely, if you go to CSU, you'll be doing what you're best at and enjoying the learning more, and most likely feeling more comfortable in the classroom. However the two majors are pretty similar so this isn't a killer. Also, you'll be coming out with less debt and your life after college will most likely be a hell of a lot less stressful.
So... you go to Purdue. You'll most likely like it much more because you've always wanted to go, and you'll probably be a lot happier while at school. Plus, you don't have to life with your parents anymore and have more freedom (yay for bad choices!). Through this, you will most likely meet more friends and have a better college experience. You may graduate with more debt, and regret this, but you won't have the social regret you'll have from passing up the opportunity to go to your dream school.
But really talk to your family and your friends who are going through the same thing, or talk to people who have had to make similar decisions. They'll help you much more than we here at MCG would most likely be able to do.
Good luck!