From my personal opinion, I still have a preference for baby sling. It's not that carriers are not good but I love the closeness with baby when using a sling. Carrier will be a good replacement when your child is above 6 months as good carriers can help to keep your posture and reduce backache problems.
For baby sling, you can check out Pupsik Studio where they have a wide range of prints for selection. Prices range between SG$45.90 to SG$59.90
For baby carrier, I will recommend Beco baby carrier. Beco carries 2 collection: Butterfly 2 and Gemini ~ Made of organic cotton