Kokoda trail or Bulldog track on the "cheap"

I am looking at doing the Kokoda trail, not because I have a particular desire to, but because I am trying to travel from Port Moresby to Vanimo by land, and apparently it's one of the only ways (other than the bulldog track).

Is it possible to do this without spending thousands?

If I can't get from POM to Vanimo without flying, unfortunately I'll have to change plans and start my trip in indo :(

Thanks!

PS. my entire trip is basically from sydney to europe overland (the only flight i'm prepared to take is either from Cairns to POM, or if PNG is out of the question, Sydney to Denpasar