The internal cost per tonne to low Earth orbit differs
vastly between SpaceX’s Falcon 9 and Ariane’s best offer:
Vehicle Cost / tonne
Falcon 9 (booster recovery) ~$2 million
Ariane 64 ~$5 million
Starship (projected) <$500,000
To meaningfully compete, European launch providers must try to match these costs, then spend a decade putting these vehicles into orbit. That’s no easy task.
Source? Quick search did not reveal any internal cost per tonne to orbit numbers.
Either way, if they did outsource these launches, they would not be paying the cost, but the price (meaning cost + margin). And that is much more expensive then just buying it from SpX.