An example from me. Several months ago I was looking for info on aquariums and was referred to the Bird market in Denpasar. I went there with Made and an aquarium the size I wanted.... but not really the style I wanted we were quoted 500,000. Last month, I went back alone as my fish were getting too big and I needed something bigger, even if I didnt like it, that would do until I could afford somthing better..... I got the same aquarium for 190,000.
I used to think it helped bring Made along, now I am not so sure! I think if they see what they think is a rich Indonesian (Made isn't) they charge even more!
I actually know some people with businesses that charge domestic tourists more than international as they say they are on holiday for 4/7 days with a load of money whereas backpackers have a load of money but to last a year....