I found a PDF file from ICAO with the block operating costs from Summer 2000, for many of the A/C in the game without any current operating cost info.
Fuel flows are based on that data, I created a calculator for them as best I could. Great document but pitty it doesn't have more data.
Yes, I wish also it had a better description of what costs are included. But considering just how many aircraft in the game have no costs beyond fuel costs.
The 319 in game shows $692(using my kids computer, no euro symbol) and the ICAO report shows US$ 698 fuel costs in Summer 2000. But it shows a total block operating cost of $ 2,156
The 343 as 1,771 in game, and 1,848 from the ICAO.