Hey mate,
I usually do one every winter, this year likely included. Typically do I detour via feathertop because I like it.
Yes it (usually) passes through the ski zones, no you dont have to pay a cent, unless you plan to park your car or stay at the accommodation at either end. Bus services run to both resorts regularly from melb - if that where you live it's quite viable to bus all the way to one resort, do the hike and bus right on home.
As far as the hike, maaany different paths to take. Fairly straightforward stuff if you've done cold weather trekking before, although depending on the route you pick it can be a bit of a slog (Diamantina Spur, anyone?). 3 days is a comfortable pace, lots of detours to take if you have more time. Huts along the way if you need em, though condition and wood stock can vary so bring your own house too.
If it's your first time hiking in snow, might be worth doing something smaller to test your snowskills first - if the weather turns halfway in, you can get quite isolated pretty quick out there. Learn how to make a snowtrench (or at least dig your tent in), practice some nav in snow, pratice snowshoes in a pack, google some of the basics on avalanche awareness - that sort of thing.
Other than that? Pack some extra socks and go for it.
Feel free to ask any me more q's.
