The T4 Super or T5's claim to fame is its above average lens at a relatively low price (ie value for money) during its production run. The lens isn't really SPECTACULAR or anything close to it. The price, however, was something to sing about. Unfortunately, the good value is no longer there if you manage to find one on the used market.
For the kind of elevated prices that people are asking second hand, you can probably find a few other cameras that can give you the same quality of pictures in a superior camera body.