It about 20-25 minutes from campus. I'm not sure what the traffic is like during the morning commute. Unless you are getting a smoking deal in El Mirage, I think you should come a little closer.
I don't think the drive is that bad in the morning. El Mirage is really not that far from the campus. I would say it is more like 20 minutes, but the extra time would be from the weird layout of the city. Grand Ave runs north of El Mirage and cuts off access of several major streets. There is basically two ways in and out traveling west, so it can be kind of a pain. Also, there are a lot of foreclosed homes in the area, so some neighborhoods are not the best. AND, there is a stupid camera on the biggest intersection there that WILL GET YOU A TICKET AT SOME POINT!!! My husband drives up there for work often and has had 3 tickets this year alone. He now goes a different way to work. That camera actually is the highest grossing camera is Arizona, and gives out 6k tickets per month! If you find a good deal though...