My general experience so far with colleagues and friends is that the younger single crew appear to be attracted towards Clarke Quay / Robertson Quay / Bugis... familes seem to have a habit of heading further out along the east coast where you get much more space, and the lazy gits among us end up 2 ...
When I moved here back in November, most 1br places in condos in River Valley were going for just over S$3k... although I get the feeling the market has definitely softened considerably since then. I'd second Andrea's comment that you can probably pick up a 1br apartment for closer to S$2.5k by now....