If it is already truncated in the beginning (and at every step of the calculation) for 0,001 of a share, you should divide the Investment amount from the 1 EUR by 12,3 cent and not by 12,345 cent. This would then give you 8,009932 truncated to 0,008 shares.
This translates to 0,9876 EUR truncated to 0,987 EUR. Adding 1,5% = 0,0147 EUR truncated to 0,014 adding up to 1,001 EUR truncated to 1,00 EUR.
Is it at every step of the calculation?
