Pair cashed in with drugs scam.
Boxes of khat, which produces an amphetamine-like effect when chewed, were then sold on the black market for more than 10 times its value in Britain.
The drug, a plant grown largely in Kenya and east Africa, sells for around PS3 a bunch in the UK but it is banned in the US, where its value rockets to about $50 per "piece".
Hundreds of parcels were shipped to the US during the conspiracy, between January 1, 2009 and May 2 last year, jurors heard.
Daud Ali, 42, from Cardiff, and Sharif Ali, 46, from Pioneer House, Hillfields, Coventry, were allegedly part of a group who mis-labelled parcels in a bid to deceive customs officials, stating the contents included computer components, wedding dresses and barbeques.
Lelah Ali, 46, her partner Adrian Wall, 50, Hersi Farah, 48, and Warsame Nuur, also of Hillfields, 48, have admitted being involved in the plot, jurors heard.
All four, together with Daud and Sharif Ali, were said to have received at least $500,000 (PS311,000) from the sale of the stimulant.
Daud Ali, of Wakehurst Place, Cardiff, and Sharif Ali, of Pioneer House, Adelaide Street, Coventry, both deny conspiracy to commit offences under Section 167 of the Customs and Excise Management 1979.
The trial, which is expected to last around six weeks, continues.