I have Canon imagerunner advance c3520i , Toners C-EXV 49 TONER BK: 36,000 pages 50 euros and C-EXV 49 TONER C/M/Y: 19,000 pages 80euros each. Can someone tell me the average toner cost of an A4 photo print one side of the paper (for example 80% coverage that most photos have)?