15-20% above market price no problem to them as long as they like. However, they are also not stupid lah, and they are also quite opportunistic. They will try to offer low see whether you bait or not, then slowly bring up the offer price. Must have patience with them.
Transactions will definitely drop for next 1 month, and there may be a few kang-cheong spiders selling below current market price. These new rules will allow those with lots of cash and holding power and waiting to buy to get in at cheaper than current market price (but the windows will be very short). However, as long as Singapore's economy continue to grow, S$ continue to appreciate, more foreign money will continue to come in and soon the prices will continue the climb again within 2-3 months. Let's see.