The solution involves two words.
Don't increase GST - that simply increases the viability of a free (black) market in secondhand goods, and adds to compliance costs for business.
Don't create new taxes, because it will create new ways of evading and avoiding them.
Don't even start to believe taxation on real property will address speculative bubbles in the housing market, look at how the RMA, the absurd obsession of councils with the discredited "smart growth" philosophy, the central banking system and most of all, taxes on other investment, create distortions.
So think about this John.
If income and company tax were reduced to a simple 20% with the first $10k tax free (hardly radical and not Libertarianz policy), then how much MORE would that encourage a shift of investment from land to business? Do you really think you and your crew know better how to spend more than that proportion of New Zealanders' income than they do?
If the RMA and tinpot planners in local authorities (especially the new uber council for Auckland) stopped restricting how people can build housing on land, without threatening the property rights of their neighbours, how much supply would be unlocked to ease pressure on prices?
How about a bottom up review of the central banking system, inflation targets and prospects for reform of that?