DEREK Brawn, the ex- Savillsemployee who told all in a book about the property business called Irelands House Party is back in the spotlight again - this time with a new website. His comparebuy2rent.ieaims to help first-time buyers decide when to pounce, thanks to a "dynamic" calculator that will work out whether it's worth buying now, or later.

So what has this calculator got in terms of seeing into the future that the rest of us don’t?

Apparently it uses the same information to calculate risk the banks do when assessing mortgage markets. When Around the Blocktried to assess the wisdom of buying a €200,000 property, it was more than a little bamboozled at the level of economic forecasting required to use this tool. It's not just a case of typing in the price of the property and the mortgage amount and pressing a button.

Instead you have to guestimate the fluctuation of interest rates, as well as predict how property prices and rents will fare over the next five years.

The verdict read a bit like a Magic 8-ball. “Do not buy now, rent for five years then look at the market again” . . . but could this be because some of our projections were wrong?

Brawn,a self-confessed math’s freak admits “Yes, it’s complicated, but you know what, finance is complicated, getting a mortgage is complicated. If you take the time to do this, you could save yourself some money.”

He says the verdict delivered by the calculator on whether to buy or hold off until a later date is not his verdict “but the financial consequence of your own opinion”.Brawn insists it’s like learning to drive and anyone who uses it will soon get the hang of it – and there’s a “how to” section to guide people through.

But what if there are more shocks coming down the tracks that his calculator hasn’t bargained for? “There could be some interest rate suprises and the real surprise would be if we see another quarter like the last one in terms of house price drops. But we need activity, we have to get people making transactions.”