You can thank all local train operators for this. They have been fighting a shared ticketing system tooth and nail at the European level and the weak politicians in Europe who don't push for a shared system.
What is the rationale for fighting a unified system? A unified system would make it easier to travel by train, which should in theory encourage people to do so more.
Is this a problem of the operators within each country not wanting to be unified with each other because then they'd have to compete more directly? Or is this actually the operators between countries fighting over it for some reason?
It's just price differentiation in action. A Polish ticket for the same train can be a third of the price of an Austrian ticket. People are rightfully pissed when this happens to them online, yet they seem to accept it for trains. I don't understand it.
Austrians moving to Poland doing any specific job will pe paid exactly the same as the Polish. Similarly a Pole working a job in Austria is paid the same as an Austrian doing the same job.
The fact that there might be a wage difference between different countries might be interesting, but it us utterly irrelevant to the fact that there is a price difference between tickets sold for the exact same train. Not an Austrian vs. a Polish train -- literally the same actual train with the same finite, exact seats for sale.
I had a good experience earlier this year on a Paris/Berlin/Vienna/Venice/Stuttgart/Paris loop using raileurope.com and nightjet.com
I guess it may be more expensive but I don't mind, I find the booking experience very clear cut as to what is refundable, what is nonrefundable etc, easy to pick which class for each segment and so on. no complaints.
You can (except for Germany I think, that stopped accepting the tickets issued from international tariff book few years ago), but this will get you the base price, without any possible discounts, so is usually way more expensive than tickets bought directly. But gives you tickets with date change/cancellation possible.
Not needed, at least in most Europe. Operators share data and you can get timetable information from any of them for all trains, including combined itinearies, and the expectation is you get information from your local train company.
just booking a train and getting a quote crossing multiple borders (without interrail) is just a nightmare :(