A road trip including a ferry takes 8h 23m, and needs driving 600km * 4l/100km = 24l of diesel, which is about $56 just for the fuel.
Then add the value of your free time, which is necessarily higher than your work time, because you have less time left in a week.
For example, having more free time is probably not adequate compensation for the greenhouse gases emitted (at the societal level at least).
The EU has emissions caps. Each year fewer and fewer carbon emissions rights are auctioned out.
https://ec.europa.eu/clima/eu-action/eu-emissions-trading-sy...
Maybe it doesn't yet reflect the externalities on the environment. But it eventually will. The 2030 target is set so that the EU becomes climate-neutral.
https://ec.europa.eu/clima/eu-action/climate-strategies-targ...
Until that time, I'll take the plane whenever I feel like it.