I did this walk a few years ago, jumped on the Vline from Melbourne to Mt Beauty, and got a taxi from Mt Beauty to Mountain Creek. Although, I walked this in the opposite direction, here's what I did:
Day One: Mountain Creek to Bivouak Hut (Was late in the day, started walking around 3pm)
Day Two: Bivouak Hut to Big River via T-Spur.
Day Three: Big River to Wallace Hut via Mt Nelse
Day Four: Wallace Hut to Blairs Hut via Cope Hut, Mt Cope, and Lake Spur (where Westons Hut used to be)
Day Five: Blairs Hut to Federation Hut via Diamantina Spur
Day Six: Federation Hut to Harrietville via Bungalow Spur
To get back to Bright, I ended up hitching a ride with someone I met up at Federation Hut, however the taxi from Harrietville to Bright didnt cost me more than 30 - 40$ from memory.
If I were to do the same walk again in reverse, but drive in, I would probably park at Mountain Creek, and arrange a taxi to Mt Beauty in time to get a bus through to Bright, then from Bright, a Taxi to Harrietville. Cant remember if busses run that way or not, but worth a look for sure. Might cost a bit in taxi fees, but its the most straight forward way I've done it.
As for the walk, its an incredible walk. One of the best that I have done, and hope that you thoroughly enjoy it. Do not miss Feathertop, or the climb up/down Diamantina.