In June 1985, the CPC 664 was launched at 4490 Francs for monochrome and 5990 Francs for colour. Source: Micro 7 #28 - 06/1985
The evolution of Amstrad CPC prices over the years is described in that article: [https://www.cpc-power.com/cpcarchives/index.php?page=articles&num=90 L'histoire des CPC selon GENERAL]
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