Ryanair do show the cost of hold luggage, and whilst such surcharges are irritating, they are balanced against an often cheap base price.
The 'Ryanair experience' is pretty scummy. The worst sort of passenger herding, irritating attempts to sell extras (when booking and in-flight) and a strong degree of deception in how they present prices vs. more hidden costs. We've still used them, where the arrival/departure airports are convenient.
# of train changes is a big factor for that travel. If having to change trains at Roma, then that's a lot less appealing that a 7 hour direct train. With the latter, once on the train you can settle in and relax, have a lovely picnic, maybe even a snooze. It's always easier to stretch your legs mid-journey, plus it avoids the passenger herding of modern air travel.
Booking a few month in advance for both travel methods usually gets the best prices.
Finally, this won't appeal to everyone, but there are some overnight sleeper trains, and that can be a different experience.