I've seen this somewhere else - booking the ticket & seat reservation separately. Question: how do they match the ticket with the seat reservation? Or are they totally separate? - in which case i guess someone could block a seat and prevent someone else reserving/using it for just €3.
Regarding my journey (Budapest - St Anton) - it is still not showing for my dates ton OEBB though as
railways states above it can be booked on MAV (to Zurich). I'm going to go ahead and book on MAV 1st class (€59) . Question: will I be able to reserve a business class seat on top of the MAV booking (which I think includes lounge access in Budapest + meal on train) on OEBB when it becomes available on OEBB (looks like business class costs just €15 extra).
Edit: I just tried to book 1st class on MAV. I'm actually booking for 2 and it looks like the €59 1st class for one person is an error. When I change to 2 people it quotes €158 (€79 each), so not quite as good a deal as originally thought. I could try booking 2 separate tickets at €59 and then hope to reserve business class seats together later on OEBB but there's a risk we wouldn't be seated together if that strategy failed.