Hi Nway,
We chose Colonial @ Scotts as our wedding reception was only a small affair for 60+ people. Different time slots have different rates so you might like to check with the person i/c Vanita to get the latest rate card. For our wedding lunch slot from 12-3pm, venue rental was $700. We then added an additional hour for $100 as I wanted my caterer to come in earlier to set up and also we needed time to decorate the place. I was sprinkling rose petals at the entrance area, haha.
Also, as we brought in our own caterer, we had to pay an outside catering surcharge of $500. But if you decide to use theirs (the owner of this venue is also the owner of Song of India), then there is no need to pay surcharge. But I didn't fancy their buffet menus so I engaged Lavish Dine instead. Colonial @ Scotts charges only 5% incidental charges, no GST or service charge but you have to pay a refundable security deposit of $200 which you can get back after your event.
Hope this helps and good luck with your planning!