Hegarty said the total value of the coins was "very close to £3 million".
Following the discovery in June 2015, co-defendant Paul Wells, 60, introduced the pair to a Cardiff antique dealer, who was shown a sample of "12 coins which had the names of Alfred and Ceolwulf and were plainly from the Anglo-Saxon period", jurors heard.
The men told the dealer they had between 200 and 300 coins and also showed him a "thick gold ring, a dark-coloured bracelet with a serpent's head on it and a pendant with a crystal centre and a band of gold", the court was told.
Hegarty said the dealer advised the pair to declare the find on a farm outside Leominster, Herefordshire, to the local coroner, in accordance with the law. But jurors heard they failed to notify the landowner or the coroner.
They eventually approached the National Museum of Wales's finds recovery co-ordinator a month later - after a council finds liaison officer heard rumours of the treasure and tracked one of the men down by email. The court heard the pair signed the three items of jewellery over to the museum's portable antiquities division, but claimed to have found only one coin each.
Hegarty said only about 30 coins were recovered, adding that 23 were passed in two batches to Simon Wicks, 57, the fourth member of the "conspiracy to convert criminal property into money".
Powell, of Newport, South Wales, and Davies, of Pontypridd, Mid Glamorgan, both deny theft. They are also charged alongside Wicks, of Hailsham, East Sussex, and Wells, of Cardiff, with conspiracy to conceal criminal property.
The trial continues.