The army's plan to procure eight AH-6i helicopters and other equipment will actually cost 4.2 billion baht, army spokesman Winthai Suvaree said, correcting previous reports which had the bill at a much higher cost.
Previous reports that the US government had approved the possible sale of the eight light attack reconnaissance helicopters and equipment put the cost at 12 billion baht.
The Defence Security Cooperation Agency (DSCA), which informed the US Congress of the State Department's approval of the possible sale, said the estimated cost would be about 12 billion baht.
According to the DSCA, the government asked to buy eight AH-6i helicopters; 50 AGM-114R Hellfire missiles; and 200 Advance Precision Kill Weapon System (APKWS) rockets.
Also included in the deal were guns, other rockets, night-vision goggles, cameras, integrated product support and technical assistance.
Col Winthai said the 12-billion-baht estimate was the maximum budget that the Thai army was allocated to make the procurement. However, what the army asked to buy only amounted to 4.2 billion baht.
He said the army plans to procure a total of 31 AH-6i helicopters, adding that the eight mentioned will be the second batch after the procurement of an initial eight helicopters was approved in 2011.
Army chief Gen Apirat Kongsompong on Wednesday defended the procurement plan, insisting the proposed purchase was above board.
Gen Apirat said the proposed procurement is transparent and the choppers will strengthen the country's defence capabilities.
According to the DSCA, the proposed sale would support US foreign policy and national security objectives by helping improve the security of a major non-Nato ally.
The agency said Thailand is a strategic partner committed to contributing to regional security.
The AH-6i helicopter would improve the army's light-attack capability, strengthen national defence and deter regional threats, according to the DSCA.
The choppers would provide reconnaissance or close air support to special forces units, Stryker infantry soldiers and border guard units.