Some reference points:
★★★: most expensive
★★: relatively less expensive
★: least expensive
Palace Hotel Tachikawa★★★
http://www.palace-t.co.jp/english/index.html
http://www.palace-t.co.jp/index.html
Tachikawa Grand Hotel★★
http://tachikawa.khgrp.co.jp/
Tachikawa Washington Hotel★★
http://www.tachikawa-wh.com/
Tachikawa Regent Hotel★
http://www.tachikawa-regent-hotel.jp/
Super Hotel Tokyo-JR Tachikawa Kitaguchi★
http://www.superhotel.co.jp/s_hotels/tachikawakita/tachikawakita.html
For more possibilities, the following search links would be useful if you're familiar with Japanese websites:
Jalan
Rakuten Travel
Ikyu.com