The "net is being cast increasingly wide" when it comes to identifying subjects for the honour of being captured for posterity in the oils or bronzes that then grace the parliamentary estate, according to the TaxPayers' Alliance.
Records released under the Freedom of Information Act show the bill for a painting of Work and Pensions Secretary Iain Duncan Smith came in at £10,000, £8000 for Minister Without Portfolio Kenneth Clarke and £4000 for Foreign Secretary William Hague.
Labour's Diane Abbott cost £11,750 to capture, the same amount as was spent on a full-sized statue of former prime minister Margaret Thatcher. A painting of long-serving backbencher Dennis Skinner cost £2180 while Labour's Tony Benn and former Liberal Democrat leader Lord Ashdown both cost £2000 and another of the party's former leaders, Sir Menzies Campbell, cost £10,346.
A portrait of Commons Speaker John Bercow cost £22,000 to commission, with an extra £15,000 spent on a frame and coat of arms in keeping with other paintings in the Speaker's House.
Decisions on commissioning and buying art are made by the Speaker's Advisory Committee on Works of Art, a cross-party group chaired by Labour's Frank Doran.
Jonathan Isaby, chief executive of the TaxPayers' Alliance, said it had the whiff of an expensive vanity project, adding: "While the public might expect former prime ministers or speakers to be afforded the honour of a painting or bust in Parliament, it would certainly seem that the net is being cast increasingly wide when it comes to identifying subjects."
A House of Commons spokesman said: "The Parliamentary Art Collection at the House of Commons records those who have made a significant contribution to UK political life over the centuries and in each parliament the Speaker's Advisory Committee on Works of Art endeavours to update this record by adding to the contemporary portrait collection."