Someone has looked at the OBR figures on this.
Only around 3500 extra people will buy a house as a result of the changes.
The tax lost from all the other first time buyers who would have bought anyone, means that to benefit those 3500 people, its costing £900,000. Each.
Not only that, but the other first time buyers who think they are getting a wind fall aren't. Why? Because the OBR predicts it will merely push up prices, so they will have to pay more for a house.
This means it will make it harder for first time buyers in the long run and will benefit people who already own a home more.
When you think about all the other ways this money could have been spent, if the stamp duty was kept, it makes the policy look particularly bad.
For example: You could give 21,000 key service workers a £150,000 grant towards a property. Not a loan, a grant. Or you could build 21,000 houses for £150,000 for social rent - and get an additional return on the money.
But nope, we get a really rather unimaginative policy to try and grab headlines, which only helps a tiny number of affluent middle class people and changes fuck all else in reality. At great expense.
Yay for politics over efficient management of our national finances.