IMHO, the number of lines a system is estimated to be should not be the sole determining factor on which language to use.

As cianoz mentioned, analysis is very important. You should also consider what the program does. A few years ago, I wrote a large part of a data conversion system (that formatted gigabytes of data from different database formats to a single database format) in C.
I was required to write it in C, but I often think how much easier/shorter/more efficent it would have been if I had been allowed to write it in Perl.

Tii