My parents have the SingTel HomeLive cam and they are pretty happy with it. The subscription fees are quite reasonable, at 6.90SGD a month.
But if you're looking for a one off purchase, Lazada.sg has several options below 100SGD. They are mostly wireless cameras and don't look complicated to install.
http://www.lazada.sg/shop-ip-cameras/
Shannelle Teo