Massage
As with any trip to Southeast Asia, massages are cheap in Bali. There are especially a lot of massage shops around. So you can just pick a decent-looking one and walk right in. It varies by shop and type of massage, but for a basic one-hour full-body Balinese massage, the price seems to run around 120k rupiah.
My body felt pretty tense, so I got a massage about twice a day while in Bali. There are all kinds of massages, so I tried some unusual ones too. Foot reflexology, for instance. I personally think reflexology is pseudoscience and don't buy into it. But whatever the evidence says, I figure there's no reason not to try it if it feels good. And since it's not a full-body massage, it's much cheaper.
Having tried reflexology, I can't say I felt any particular boost to my health. Honestly, as with any walk-in massage shop, it's hard to expect real expertise in reflexology. I doubt there's much to it beyond a foot massage with some acupressure added. Even so, it did a good job loosening up my feet and calves, which were knotted from all the walking, so I was satisfied. All roads lead to Rome — whatever the evidence, all that matters is the ROI.