Translate the following English sentence to French:
"Their economies are invariably fragile ones and it is just not good enough that the farmers on the Isle of Lewis have to pay twice as much for their hay as farmers living near Inverness."
Leur économie est très fragile et il est tout simplement inacceptable que les agriculteurs de l'île de Lewis payent leur foin deux fois plus cher que ceux qui habitent près d'Inverness.