I started a similar thread a little while ago and posted my experiences afterwards. You can read for your reference.
https://balipod.com/forum/threads/import-duty-for-foreign-travellers.5652/
With that being said, if you carry large bulky boxes that look expensive then be prepared to pay up. From the experiences I had, what I have read and heard. Regardless of the law customs officials rate 10/10 on the dodgy scale. If you can fit them into your normal suit case then you might be able to get through without declaring it. I'm sure 1000s of tourists take their iphones, laptops etc and don't declare them, all of which are worth more than $250.
I, on the other hand, had to declare because it was so blatantly obvious what I had with me.