There is free street parking away from stadium
If you park a little farther away into the prospect park neighborhood(might have name wrong) past stadium village there is free street parking and such but you have to get there early enough. Some streets behind the transit way too that the buses running by wher you can park but you will have to walk. Just make sure you have someone to walk with and be cautious. Same thing with the west bank and parking near the light rail staition that is a couple blocks away from campus. you can walk and catch the shuttle on the West bank to the shuttle. I have only done this twice the other times I paid to park and took the shuttle to give the U some money. but the free street parking is your cheapest option.