In that price range, I've stayed at Carousel Inn and Howard Johnson's. I've also heard good things about Desert Inn and Suites.
Carousel is closer, but my personal favorite is Howard Johnson's. HoJo's is still walking distance, and they also have a trolley. I like the atmosphere, it's clean, and they have interior hallways, so it's more like a hotel, whereas a lot of the other ones are like motels with exterior hallways. HoJo also has lots of parking if that's a factor.