There are bunch of cheap massage joints in the Chinese neighborhood of Alhambra and Monterey Park. I usually go to the massage places near Del Mar Ave. & Valley Blvd.
As you enter these neighborhoods you'll find bunch of signs written in Chinese. The massage stores are pretty easy to distinguish since a lot of them stores would have a logo of a foot. Many stores offer foot massage (including a little bit of shoulder massages) for $15.00 / hr. You want to be aware of the fact that a lot of these stores offer $25 / hr course for full body massage. Sometimes, if you don't tell the masseuse that you want only the foot massage, they'll end up charging you for the full body massage.
I usually give them $5.00 tip, so my 1hr of foot massage ends up being $20 in total.
Another caveat is that some stores, during peak hours, they get pretty messy and loud. In that occasion, I would rather pay $5.00 more for quieter and smaller place to get a better service.
Here is my recommended starting point. Park your car in the shopping plaza with 99 ranch super market, and walk around near the Hilton hotel, and you'll at least find 4 massage places. Good luck and enjoy!!