AirBnB is probably going to be the best value for staying downtown and walking into class. Prices can be as low as $30 per night (depending on the time of year).
Next, are Hotels near the San Jose airport which are few miles away from downtown with mid-range prices. You have to catch the light rail which is a 10 min ride to downtown San Jose.
Depending on dates, prices can range from: $100-200
Hotels near downtown San Jose, but are pricey.
Depending on dates, prices can range from: $150-300
Information regarding the Light Rail Public Transport - http://www.vta.org
Gish (Next to hotels near airport mentioned) > Civic Center > Japantown > St. James (Downtown San Jose)