Translate the following English sentence to French:
"We need to introduce a system which covers the costs and it is therefore not right at this stage to fix maximum fees, which would seem premature until such time as we know the actual costs involved."
C' est pourquoi il n' est pas correct de prévoir dès maintenant une redevance maximale, car établir une telle redevance sans connaître les coûts réels est prématuré.