Punggol Place is the area nearest to the MRT and Bus Interchange. 270+ is nearer to MRT/BI than 280+ and from 270+ you can walk to Waterway point sheltered all the way. 280+ you will need an umbrella if it is raining. Hence those in 270+ typically want a premium over 280+.
Why are so many people selling? 1 reason is the price is still good for anyone who wants to sell now.
Second is, punggol resale supply is increasing, the later it is, the harder to sell.
Third, punggol flats are very new but do not have good floor plans (my personal opinion). Alot of wastage and unusable floor area. If you are really detailed, you should consider the price vs useful floor area.
Fourth, Punggol is very crowded these days. Waterway point remains very crowded over weekends even during Covid. The NTUC is jam packed with shoppers unless you decide to buy grocery over awkward hours. And Punggol will only get more crowded in the future. There isn't another mall in line in the near future (correct me if I am wrong). New mall will probably come when the govt thinks the population is enough to support it. But for now, Punggol residents are likely to squeeze with everyone else.
Fifth, families with young children want to stay closer to their older parents to take care of them or older parents to help take care of the children.
Sixth, environmental factors. Recently, the airplanes flying are really noisy and it happens very frequently. My friends staying there complain that their babies and young children cant get proper afternoon naps. Occasionally there are smells. While the airbase is scheduled to move from
2030 onwards (it can be 2030, 2031, 2032.....2040....2050......who knows exactly when), the smell is unlikely to disappear as it is from Pasir Gudang in Msia