Illinois is among the 5 worst programs in the country
It will take at least 5 years to get back to respectability...which means consistent.500 within the Big 10. Given the state of the program and facilities (3rd class would be an overstatement) as well as the economic condition of state government (already in a deep hole and getting deeper since they aren't doing anything to fix it), there isn't going to be any $$ available to make it attractive to recruits. Illinois is a fine school but Champaign is a dump and perhaps the least redeeming place to play in the Big 10.
Chicago high school football (which should be Illinois' #1 market) isn't what it used to be and Iowa, Wisconsin, Notre Dame, Michigan and some of the Big 12 schools will pick it clean before Illinois even gets a sniff. Illinois is going to have to pick from the scrap heap or find a naive up-and-comer from the secondary market.