Unlike NSW, Victoria still requires a unanimous vote for a decision to sell off all the units and the common property in an apartment block (according to Section 32 (g) of the Subdivisions Act 1988) and according to this factsheet from Consumer Affairs Victoria, a unanimous vote means means a vote all owners, not just all owners who vote.
So even if you were in the pro-selling group, you’d have to persuade the one person who has no interest in moving under any circumstances, regardless of the deal offered.
There are probably exceptional circumstances – such as the building has become unviable or uninhabitable – under which you could take legal action to force the hold-outs’ hands. But that doesn’t seem like the situation here.
Apart from all that, any offers have to be worth the current owners while. You’d be looking at not just a premium price, but one that made it worth all the hassle, plus the opportunity to buy somewhere better than where you are currently living, so I’d say one-and-a half to two times current values would be your starting point.
I wouldn’t even worry about commissions and who is in cahoots with whom. It all comes down to the bottom line of how much the developer is going to make and how much they are going to pay owners to get them to sell the whole block.
One question would be, how much would it cost for you to buy a unit in the new block.
One thing for sure, if you move forward with this but don’t act as a group, you will get screwed.
And, as I said, unless the hold-out yields or the law changes, nothing will happen anyway.