There is obvious glee within the housing market about the prospects of a two-year period free of stamp duty for those first-time buyers who purchase properties worth less than £250,000.

The £250,000 threshold captures practically all of them, with significantly less than 10% of exceptions that will be mainly resident in London and the South East.

And the cost of this "Budget giveaway" the Treasury puts at under £300 million annually at worst.

This figure is of course a hypothetical resting on the expectations built into the forecast models of how many homes within scope of the policy will actually be sold over the period.

And, on a technical note, it must be remembered that those eligible must fit the Revenue’s definition of a first-time buyer, which takes in only those who have never owned homes before. This differs from, and is narrower than, the definition used by lenders.

The Council of Mortgage Lenders, given the awkward differences of definition, tentatively suggests the Revenue might forego about £224 million as a result of the policy. That's a figure that looks good to me.

Meanwhile, to help claw back the costs, from 2011-12 those looking to trade homes worth more than £1 million will be obliged to pay 5% rather than the current 4% in stamp duty of the sale.

My quick calculation earlier on today in the heat of the Budget being delivered was that this would raise about £250 million. Fortunately the CML seems to agree. The Treasury meanwhile puts the figure at £230 million.

Either way the policy looks to be broadly balanced over the next few years.

But what is intriguing is that while the Treasury gains a positive headline for speeding more first-time buyers to the front doors of their new homes, it is not being hammered for effectively raising the level of stamp duty overall on house transactions in the long term. That is quite a neat trick.

Although some of the initial sheen on the policy may be lost as there are likely to be some gripes about the sudden jump in the tax rate at £250,000, with first time buyers paying no tax below the threshold and everyone paying 3% above it.

This may distort prices in some areas where there is significant bunching in prices around the £250,000 mark, which almost inevitably will lead to grumbles.

Furthermore as CML points out there may be problems over implementation caused by the definition of a first-time buyer.

But you have to hand it to Chancellor Alastair Darling, this policy appears to have no real net cost over the medium term but a boost to future revenue streams attached. What’s more all the signs are that it will buy votes.

Raising taxes, winning votes and gaining the applause of house builders and estate agents - hat's off.