Ah Beng,
In term of calculation, you are not wrong.
But when getting a car, one has to think of the finance side, for
example the car cost 20k more, and that person need to loan 20 more
thousand, that would mean more interest every month. Yes I do agree
that overall a new car is more worth it but the bottom line is how
tight the budget is, or how much interest do you think you can
afford to pay. Also, the Insurance ($$$). Old car definitely have
cheaper insurance cos most insurance are based on the market value
of the car. A 20k difference in value would mean a saving of at
least a few hundred dollars per yr.
Another thing to think of will be what car that person like. Some
personally prefer honda, while some nissan or toyota. For 63k, I
think you can get quite a few brank new car like the Kia Rio 1.5,
Hyundai Getz 1.4 etc. So it all boils down to what he like.
You might not have realise as well, in fact the old 1.5Vti
performance is almost on par with the new 1.6Vti. I have done a
little reading on the 1.5Vti and 1.6Vti before, though not those in
depth kind of study. So I can boldly say that a 1.5Vti is as good
as a 1.6Vti. And guess what, a 1.5Vti means you get to pay slightly
cheaper road tax. 
Not a lot but when the time come, even a 100 dollars
or 50 make a difference, thrust me. Of cos unless you are earning
4-5k a month salary.
