Did you children heard the news about Legoland? You better save the 2013 budget specifically for this because the theme park is not like other theme park in Malaysia. Legoland is design specifically for families with kids from 3-11. So in theory your children will not get bored easily. If your kid have the original lego set at home then they will easily get attached to the theme park.
At airasiaredtix.com, you can buy a limited amount of discounted pre-opening annual passes. With the pass, you can get unlimited access to the park until 31.12.2013. So check the availability at airasiaredtix.com or legoland.com.my.