I highly recommend you time your trip to be at the Skypark at sunset. That’s when you get majestic skies and the city lights twinkle and awaken. If you wait even longer, you’ll get a light show on the Harbour (but I disappeared before then to grab a bit to eat).
The Skypark itself runs like a machine. It costs about $26SGD per person to get to the top, and you’ll find it can get very crowded up there. There are trinkets and food/drinks available up there but if you don’t want to be hit by tourist prices for a meager hot dog, then eat before you go.
There’s always the option of having dinner up there, but reserve a place as I don’t think they take walk ins and it gets filled pretty quickly. Also, don’t expect to be anywhere near the famed infinity pool. Lastly, the queues to leave are long and windy as there are only 2 lifts available up to the SkyPark, so leave yourself a loose schedule because you could be waiting a while to get down.
All in all, the experience is worth it. The panoramic views are breathtaking and the rest of the experience is just incidental.