Petronas towers from the Kuala Lumpur tower
I did it and arrived at the foot of the Petronas at 7 in the morning and there were almost 100 people in the queue waiting for the doors to open an hour and a half later. After the wait they informed me that it was only possible to go up to the Skybridge -the passage that joins both towers at medium height- by 40 ringgits.
The experience was interesting, but if I went back to Petronas and never started eating that tail for so little in return. At the end of the day you are inside the towers and what you see is the outside. You have much better views from the Kuala Lumpur Tower although less aesthetic (38 ringgits).
There is another option even better and above for free. In front of the Petronas towers is the Mandarin Oriental Hotel. Wear half a dress with a shirt and pants, enter the hotel reception and head left as if you knew where you are. In short, as if you were a customer of the hotel. If necessary, say hello to the bellman and you get into the elevator that you will see in the left part of the hall. Go up to the last floor. You will reach a terrace with formidable views of the Petronas towers. Skip the line and completely free. As you contemplate the views, look down and laugh at the early risers, wait and ringgits that others release.