Not so much a comment on the the course content, more the price.
$23k for a Diploma sounds steep. A comp sci degree costs less than that at some unis.
The course seems to have a lot of fluffy crap in the core subjects. None seem to be engineering focused they are all industrial relations, business and communications units. Some have an engineering flavor to them. They started to add this stuff back int he 80's.
All the engineering units seem to be in the electives even those seem light on.
In the 80s these courses had a lot more math and electronics theory in them. There may be more practical content these days.
Maybe see if you can find a lecturer for the course to chat to. The course adviser guys may not be the best source of info on the usefulness of the course.
Good luck.