Best time to enter Sentosa is on Weekday from noon to 2pm.
Entry $2 + Carpark free = total $2
So they are encouraging lunch crowd here.
Next best time is Weekday 5-7pm.
Entry is $2 (down from $5) + Carpark $1 (down from $3/ first 3hrs) = total $3.
This is probably to attract after office early dinner crowd?
Anyway…. $2 or $3, that’s cheap for Singapore. Just make sure you plan the entry time well.