The cost of classy city centre pads in Dublin has gone through the roof in recent weeks. Agent Sean Davin bought three of these recently for top businessmen who spend the odd week night in the city. In the first instance, he paid £1.3 million for a smart duplex apartment opposite Government buildings at Dunloe Hall, on Merrion Street. The price for the 2,150 sq. ft flat worked out at £605 per sq. ft. Last week, he went one better when he paid £690,000 at auction for a two-bedroom, 1,050 sq. ft apartment at Hazeldene, on Anglesea Road, in Ballsbridge. The price breaks down at £657 per sq. ft. Yesterday he splashed out £550,000 for an apartment on Clyde Road - the equivalent of £423 per sq. ft. Where will it all end?