Or, take the less expensive Keisei Skyliner to Ueno and stay in a less expensive hotel. The area around Ueno station has some nice sights to see but for nightlife you should ride the Yamanote Line or the subway Ginza Line to a better area. Just be sure to get back to your hotel by midnight or so as the trains stop running around then.
Keisei has a Skyliner + Metro pass that will give you a day pass on the subway. Asakusa is 2 stops away, as is the Tokyo Station area.