Flight Brisbane Airport departs from Brisbane Brisbane Airport at 14:15 and arrives at Melbourne Melbourne Airport at 17:35.
The flighttime is about 3h 20m. The distance travelled ("as the bird flies"): 1343 Km. So the average speed is roughly 403 Km.
The best day to arrive at Brisbane is Wednesday and it would be best to avoid Friday, as prices are on average 83.24% higher than on Wednesday. (Average prices, based on 1167440 datapoints.)
We have a lot more statistics for flights QF 625 and between Brisbane and Melbourne.