Sulawesi traffic can be bad at times and Indonesian traffic is much worse than any other asian country I have been in - and thats most of then including India, China and Vietnam - didnt ride in Vietnam though. But Sulawesi is one of the better places in Indonesia after all. I sweared all day inside my helmet - but in the evening I stil had a big grin on my face.
Its the shear amount of vehicles and the narrow roads that are the biggest problem and then there are the chaotic and jammed traffic in addition.
But dont let that scare you from going there. Its worth to swear a few times pr day to have that experince.

My average budget in Indonesia was around 30 Euro a day. You can do it even cheaper. I didnt stay in the rock bottom priced accomodations and I did eat others than rice and noodles now and then. So as I said - its possible to do it even cheaper. Its possible to find a room from around 100 000 rupiah - which is around 6-7 Euro pr night. An average rice or noodle dish is 10000-20000 in cheap eateries. Dinner with a bit of meat or seafood and vegetatables around 30-60 000 rupiah. More if you go to a upscale restaurant of course. Gasolin 88 octan is fixed price (government subsidized) 7300 rupiah pr liter - 0,5 Euro.

There are enough guesthouses and cheap hotels to get on by. Theres no need to bring camping gear. There is a long stretch from Palu to a small town called Marisa which I think is around 400 kms where its quite remote and no towns and thus no accomodation. And 400 kms is a very very long days ride in Indonesia. So that day you have to start early from Palu.
And dont ride in the dark. There will be vehicles without lights, cattle, wildlife etc on the roads so its dangerous.

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In the end everything will be fine. If its not fine its not the end....