Here is the problem. You will be paying some $120,000 extra up front (after interest), under the assumption that you will make enough more to pay it back.
This assumes that
A. You will indeed make this much more, on average, every year, for the entire period that it will take you to pay the loan back (around 8 years). The difference will likely drop, as experience becomes more important than where you did your degree. Moreover, this is the average, not the median, so you really do not know what the chances are that you will make that much more a year as your starting salary if you attend UIUC.
B. That you will get a job as soon as you graduate, AND that you will work without interruptions for the entire period.
C. This is true for your particular area in engineering.
There are two very important additional facts:
A. transfer rates from engineering are high, and
B. Four year graduation rates from Grainger are 58%, and 6 year graduation rates are 76%.
So there is a 42% chance that you will have to take further student loans, so you will owe a lot more when you graduate, and a 24% chance that you will take even longer, or not graduate with an engineering degree.
So there is a very good chance that you will either need to pay back closer to $200,000, and/or will not have that much higher a salary than if you attended ASU, because you would not graduate with an engineering degree.
Do you have that extra $100,000 on hand, AND do you not need the extra money that $100,000 would generate in the time between when you start school and when you are able to save that much on a higher salary? If so, attend Grainger. Otherwise, I personally think that it is, financially, a bad idea.