I'm speaking from personal experience. Been trying to wait for prices to fall and buy a cheap flat, but it's been a very disappointing experience. HDB valuations stay constant. Condo prices never change. Worse still, sellers still asking for loads of cash above valuation.
And they manage to sell, because PRs are flooding the market for buyers. They can pay loads of cash above value because their financing structure is different from sinkees. For us it's CPF vs how much more cash. For them it's securing a bank loan to cover 80-90% of price.
I have seen a few good units that cannot sell because the lift upgrading is in process and PRs must pay 30K cash for that, so they shun them. And these units can't sell. Why? Buyer market for locals is very small!