Two units 1.0 MVA Capacity diesel engine generator set were purchased six years ago at a cost of 7,000,000. It was estimated to have a useful life of 10 years with a salvage value of 300,000 at the end of the life. Due to an unusual problem, the company decided to replace the units and can be sold only for 790,000 per unit. Determine the sunk cost of the two units if depreciation has been computed by the double-declining balance method. (use the full decimal places)