Thanks for all the helpful responses. Spent most of the day today checking out different places, including Tueku Umar and a few in Galleria.
This is what I found:
1. Treadmills in Bali cost approximately 3-4 times as much for similarly spec'd models in Australia. i.e. a treadmill of 4 continuous HP with a thick belt, 100 different programs, big LCD display and speakers can be found for $500-600 in Australia. Here you are pushing to find a model with 2 continuous HP and half of those perks for $1500-1900.
2. Apparently this is because of the luxury tax on sporting equipment in Indonesia, though it applies equally to equipment made here (e.g. AIBI) which seems odd.
3. Almost all of the models available here are very old and have been discontinued for years, making it difficult to find information about them.
4. There are a few cheap/rubbish models and a few super high end pro/commercial models, but very little in the mid-range.
5. The people selling them know almost nothing about the products and can't even give you basic specs.
6. Stores in Tueku Umar, Galleria & Carrefour are all FitPlus, but they all carry completely different models.
Having said that, I really want a treadmill and have decided that I will buy one anyway even though I'll be paying double what I originally budgeted. Treadmill-purchasing adversity is a small price to pay for the privilege of living here.
I'm going back to Galleria tomorrow to make a final decision. Essentially prices for similarly spec'd models are much the same in the different stores, and there are 3 places (including the Hypermart) in Galleria that sell fitness equipment so it's easiest to just go there.
Thanks again and enjoy your Bali days
