The Four Points near campus is the former Plaza Hotel. I do not know if any improvements have been made. Possibly the only upgrades would be to upper floors.
Part of the reason for the higher price is the proximity to campus. The Four Points and the Marriott are the only hotels within walking distance of campus. Also, in the past when it was the Plaza, this hotel was used to house the football team during practice and it even has been used as a temporary dorm at times (Warning!Warning!) Other options, if you are looking for a Starwood property would be the Sheraton on Grant next to Tucson Medical Center, formerly a Park Inn about 5 miles from campus(but definitely a step up from any Four Points), The Sheraton El Conquistador Resort (Resort Property) about 12 miles from campus, or the Four Points downtown (Freeway location) older, cheaper, but recently renovated, about 3 miles from campus. The cheapest would be the downtown Four Points, the most expensive would be the Resort.

As a note: since I live in Tucson, I have not stayed at any of these properties, but have visited most to visit friends, visit trade shows, eat at the restaurants,etc. My personal choice would be the Sheraton at TMC.