Coal Ltd sells a specialised piece of equpment to Oil Ltd on 1 st September 20X7 for a total price of $4m, which incorporates both the sale of equipment and support service. Due to the speciaised nature of the equipment, Coal Ltd has additionally agreed to provide support service for the next two years. The cost per annum to Ltd of providing this service will be $300,000. Coal Ltd usually earns a gross margin of 20% on such contracts . What revenue should be included in the statement of profit o r loss of Coal Ltd for the year ended 31 December 20X7 ? (计算出的答案格式为XXX,XXX,每三位数字用分隔符,但不带货币单位)