i think it really depends on what you want in life...as your earnings increases, your lifestyle changes and you tend to upgrade..then no matter how much you earn, you will be just comfortable

if you want to send your kids to private school, 10k is definitely not enough...and definitely no to overseas education...

and it also depends on when he hits 30...in 1-3 years time or in 4-6 years time...cause if the duration is longer, its less predictable as the inflation rate is volatile...