Aer Lingus have no issue investing money in the right candidate , so a few hundred Euro is of no significance to them in the greater scheme. I would suggest however if your own personal finances allow to go and get a Class 1 Medical. There has been countless people who have had their commercial pilot dream ended before it started as they had an underlying condition that made it impossible to get a class 1. Before I began my training I got a Class 1 , was definitely worth the peace of mind going forward. The airline will be paying for your future Class 1 until the day you retire.
Best of luck to everybody going forward. It is a great Company to work for.