I too will add to this..
I wanted to do biomed engineering for a long time now, but on the last trip to usyd open day I was told
"Mate getting a job in the biomedical industry is very difficult, many graduates this year in biomed failed to get a job, and those who were successful got a job as a mechanical engineer...the person who topped my course couldnt find a job so decided to study further and get his PhD"
Hence do it for the reasons named in the above post.
Also try combining it with another subject.