We have done the rounds and have always come back to 2 or 3 places. Depo Bagus in Gianyer, the boss is Andry and always gives us a discount but not the greatest for sinks but ok for toilets. (also a great place for plain coloured cement tiles, miles cheaper than anywhere else). Cancana, the big bathroom place which is on Sunset Road. For us, they looked a bit 'fly' in the first instance, but overall their prices are pretty good for santiaryware and taps and we have found no one else that can match their prices for these things. Their ranges are the best and widest on the shop floor. Depo Bangunan is just ok. Tried all the places mentioned and many many more but it always comes back to Depo Bagus and Cancana after shopping around.
We have Toto which are really expensive and we have Chinese. Sometimes you are just paying for the name of Toto.
Also have a good supplier for terrazo baths etc.
Hope this helps and if you need contact no.s etc, justs let me know.